Updated run_dev instructions.

Also, removed the deprecated --package_manager option in install_development.sh

README.adoc

@@ -60,19 +60,10 @@ cd build
 [source,bash]
 ----
 cd $SPINNAKER_HOME
-spinnaker/dev/install_development.sh --package_manager
+spinnaker/dev/install_development.sh
 spinnaker/dev/bootstrap_dev.sh
 ----
 
-The `--package_manager` argument requests the Debian Package Manager be used
-to the greatest extent possible. This permits adding new source repositories
-where package dependencies are distributed from non-standard repositories
-(e.g. cassandra). The alternative is `--nopackage_manager` to use the
-Package Manager for standard dependencies but explicitly install packages
-that come from other sources. `--nopackage_manager` is intended for
-installations where IT policies discourage or forbid adding additional
-source locations.
-
 The `bootstrap_dev.sh` script will ask to install additional components. `gcloud`
 is only needed to write releases to Google Cloud Storage, but is convenient
 to have if you plan on using or accessing Google Cloud Platform resources
@@ -95,6 +86,14 @@ chmod 600 $HOME/.spinnaker/spinnaker-local.yml
 
 Edit `$HOME/.spinnaker/spinnaker-local.yml` and set the enabled option for the cloud provider(s) of your choice.
 
+The default-spinnaker-local.yml file contains some references to environment
+variables (e.g. `${SPINNAKER_AWS_ENABLED}` and all the other upper case names
+in the providers section). These are added by the spinnaker install, which
+isnt used in a developer environment so you will need to replace these with
+literals (e.g. `true`). Minimally, set the provider `${*_ENABLED}` values. If
+they are `false` then you dont need to worry about the other attributes.
+
+
 == Start Spinnaker Services
 
 ( If you're running on Mac OS, please make sure that your redis server and cassandra server is up and running. Make sure that cqlsh is accessible in your path and you can connect to cassandra by calling `cqlsh` in your terminal ).