Update circleci for multiple python versions

.circleci/config.yml

@@ -11,11 +11,6 @@
 # Templates: see "anchors" in https://learnxinyminutes.com/docs/yaml/
 ####################
 
-common_settings: &common_settings
-  docker:
-    - image: python:2.7
-  working_directory: ~/python_mozetl
-
 install_dependencies: &install_dependencies
   name: install dependencies
   command: |
@@ -40,17 +35,8 @@ early_return_for_skip_tests: &early_return_for_skip_tests
       circleci step halt
     fi
 
-
-####################
-# Jobs: see https://circleci.com/docs/2.0/jobs-steps/
-####################
-
-version: 2
-jobs:
-
-  test:
-    <<: *common_settings
-    parallelism: 8
+test_settings: &test_settings
+  working_directory: ~/python_mozetl
   steps:
     - checkout
     - run: *early_return_for_skip_tests
@@ -60,7 +46,7 @@ jobs:
         name: run tests
         command: |
           circleci tests glob "tests/**/test*.py" > tests.txt
-            tox -- \
+          tox -e $CIRCLE_JOB -- \
             $(circleci tests split --split-by=timings tests.txt | tr -d '\r') \
             --junitxml=test-reports/junit.xml
     - run:
@@ -74,8 +60,27 @@ jobs:
     - store_artifacts:
         path: test-reports
 
+####################
+# Jobs: see https://circleci.com/docs/2.0/jobs-steps/
+####################
+
+version: 2
+jobs:
+  py27:
+    <<: *test_settings
+    parallelism: 4
+    docker:
+      - image: python:2.7
+  py36:
+    <<: *test_settings
+    parallelism: 4
+    docker:
+      - image: python:3.6
+
   lint:
-    <<: *common_settings
+    docker:
+      - image: python:3.6
+    working_directory: ~/python_mozetl
     steps:
       - checkout
       - run: *early_return_for_skip_tests
@@ -95,5 +100,6 @@ workflows:
   version: 2
   build:
     jobs:
-      - test
+      - py27
+      - py36
       - lint