Improve handling of variables. Can now define them in parent of script, script directory or the directory the simdem command was run from

.gitignore

@@ -1,3 +1,6 @@
 *~
 \#*
-.#*
+.#*
+env.local.json
+!demo_scripts/test/env.local.json
+!/env.local.json

demo_scripts/env.json

@@ -1,3 +1,3 @@
 {
-    "TEST": "Hello from the project"
+    "PARENT_TEST": "Hello from the parent"
 }

demo_scripts/env.local.json

@@ -1,3 +0,0 @@
-{
-    "LOCAL_TEST": "Hello from the local project config"
-}

demo_scripts/simdem/variables/env.json

@@ -0,0 +1,3 @@
+{
+    "NAME": "Hello from the variables subdirectory"
+}

demo_scripts/simdem/variables/script.md

@@ -4,25 +4,14 @@ In order to use environment variables, you can define one or more
 files. These variables are available in every command that is
 executed.
 
-Tutorials can carry `env.json` files in the project directory and/or
-in tutorial sub- directories. Files in tutorial sub-directories will
-overwrite settings pulled from the project directory. 
+Tutorials can carry `env.json` files in the directory the simdem
+command was run and/or in tutorial sub-directories. Files in tutorial
+sub-directories will overwrite settings pulled from the project
+directory.
 
-This tutorial defines an 'env.json' in the project directory:
-
-```
-cat $SIMDEM_CWD/../env.json
-```
-
-Results:
-
-```
-{
-    "TEST": "Hello from the project"
-}
-```
-
-It also defines an 'env.json' file in the tutorial folder:
+For example, this tutorial defines an 'env.json' in the `simdem`
+parent folder and in the `variables` subdirectory that contains this
+script. Here is the content from the test subdirectory.
 
 ```
 cat $SIMDEM_CWD/env.json
@@ -32,22 +21,41 @@ Results:
 
 ```
 {
-    "TEST": "hello-world"
+    "NAME": "Hello from the variables subdirectory"
 }
 ```
 
-The file that "wins" is the most local one, that is the one in the tutorial:
+It also defines an 'env.json' file in the `SimDem` root
+folder. Assuming you executed the `simdem` command from within that
+folder the followin command will display it's content.
 
 ```
-echo $TEST
+cat env.json
 ```
 
 Results:
 
 ```
-hello-world
+{
+    "TEST": "Hello from the SimDem project"
+}
 ```
 
+Finally, a project may define an `env.local.json` file in the
+directory from which the `simdem` command is run. This file is the
+last to be loaded and overrides all other values.
+
+Values are loaded in the following order, the last file to define a
+        vlaue is the one that "wins".
+        
+    - PARENT_OF_SCRIPT_DIR/env.json
+    - SCRIPT_DIR/env.json
+    - PARENT_OF_SCRIPT_DIR/env.local.json
+    - SCRIPT_DIR/env.local.json
+    - CWD/env.json
+    - CWD/env.local.json
+
+
 ## Interactive Variables
 
 If you include an environment variable that isn't set, SimDem will prompt 

demo_scripts/test/env.json

@@ -1,3 +1,3 @@
 {
-    "TEST": "hello-world"
+    "TEST": "Hello from the test script"
 }

demo_scripts/test/env.local.json

@@ -0,0 +1,3 @@
+{
+    "TEST": "A local hello from the current working directory (where the simdem command was executed)"
+}

demo_scripts/test/script.md

@@ -21,10 +21,114 @@ echo $SIMDEM_CWD
 
 Results: 
 
-``` Expected similarity: 0.9
+``` Expected_Similarity=0.9 
 demo_scripts/test
 ```
 
+# Configuraiton Check
+
+We should be able to retrieve environment variables from the directory
+in which the command was given:
+
+```
+cat env.json
+```
+
+Results:
+
+```
+{
+    "TEST": "Hello from the current working directory (where the simdem command was executed)"
+}
+```
+
+We should also be able to retrieve locallay defined environment
+variables from the directory in which the command was given:
+
+
+```
+cat env.local.json
+```
+
+Results:
+
+```
+{
+    "TEST": "A local hello from the current working directory (where the simdem command was executed)"
+}
+```
+
+There should also be environment variables in the the directory in
+which the current script resides.
+
+```
+cat $SIMDEM_CWD/env.json
+```
+
+Results:
+
+```
+{
+    "TEST": "Hello from the test script"
+}
+```
+
+Local variables can also be found in the the directory in which the
+current script resides.
+
+```
+cat $SIMDEM_CWD/env.local.json
+```
+
+Results:
+
+```
+{
+    "TEST": "A local hello from the current working directory (where the simdem command was executed)"
+}
+```
+
+For the `TEST` variable we should have the `env.local.json` value from
+the directory in which the application was executed.
+
+```
+echo $TEST
+```
+
+Results:
+
+```
+A local hello from the current working directory (where the simdem command was executed)
+```
+
+And finally there should be variable definitions in the parent of the
+current script directory:
+
+```
+cat $SIMDEM_CWD/../env.json
+```
+
+Results:
+
+```
+{
+  "PARENT_TEST": "Hello from the parent"
+}
+```
+
+Since the value of `PARENT_TEST` is only defined in this file we
+should have the value from there:
+
+```
+echo $PARENT_TEST
+```
+
+Results:
+
+```
+Hello from the parent
+```
+
 # Simple Echo
 
 ```
@@ -37,20 +141,6 @@ Results:
 Hello world
 ```
 
-# Cat a file
-
-```
-cat $SIMDEM_CWD/env.json
-```
-
-Results:
-
-```
-{
-    "TEST": "hello-world"
-}
-```
-
 # Code comments
 
 ```
@@ -79,23 +169,6 @@ Results:
 Tue Jun  6 15:23:53 UTC 2017
 ```
 
-# Sudo
-
-NOTE: there is no sudo in Docker containers, so we need to strip
-`sudo` from commands if running in a Docker container. If we are not
-in a container we need to run SimDem as `sudo`. This test should pass
-in both scenarios.
-
-```
-sudo echo "Sudo Works"
-```
-
-Results:
-
-```
-Sudo Works 
-```
-
 # For Loop
 
 ```

env.json

@@ -0,0 +1,3 @@
+{
+    "TEST": "A local hello from the current working directory (where the simdem command was executed)"
+}

env.local.json

@@ -0,0 +1,4 @@
+{
+    "TEST": "A local hello from the current working directory (where the simdem command was executed)"
+}
+

simdem.py

@@ -33,11 +33,23 @@ class Environment(object):
         self.set("SIMDEM_CWD", directory)
 
     def read_simdem_environment(self, directory):
-        """
-        Populates each shell environment with a set of environment vars
-        loaded via env.json and/or env.local.json files. Variables are loaded
-        in order first from the parent of script_dir, then script_dir itself.
-        env.local.json > env.json.
+        """Populates each shell environment with a set of environment vars
+        loaded via env.json and/or env.local.json files. Variables are
+        loaded in order first from the parent of the current script
+        directory, then the current scriptdir itself and finally from
+        the directory in which the `simdem` command was executed (the
+        CWD).
+
+        Values are loaded in the following order, the last file to
+        define a vlaue is the one that "wins".
+        
+        - PARENT_OF_SCRIPT_DIR/env.json
+        - SCRIPT_DIR/env.json
+        - PARENT_OF_SCRIPT_DIR/env.local.json
+        - SCRIPT_DIR/env.local.json
+        - CWD/env.json
+        - CWD/env.local.json
+
         """
         env = {}
 
@@ -68,6 +80,19 @@ class Environment(object):
                 local_env = json.load(env_file)
                 env.update(local_env)
 
+        filename = "/env.json"
+        if os.path.isfile(filename):
+            with open(filename) as env_file:
+                local_env = json.load(env_file)
+                env.update(local_env)
+
+        filename = "env.local.json"
+        if os.path.isfile(filename):
+            with open(filename) as env_file:
+                local_env = json.load(env_file)
+                env.update(local_env)
+
+                
         self.env.update(env)
 
     def set(self, var, value):