updated the CircleCI config file to use multiple Python versions

#53

.circleci/config.yml

@@ -1,54 +1,106 @@
-# Python CircleCI 2.0 configuration file
-#
-# Check https://circleci.com/docs/2.0/language-python/ for more details
-#
+version: 2
+workflows:
+  version: 2
+  test:
+    jobs:
+      - test-3.7
+      - test-3.6
 jobs:
-    build_3.7:
-        docker:
-            # specify the version you desire here
-            # CircleCI maintains a library of pre-built images
-            # documented at https://circleci.com/docs/2.0/circleci-images/
-            - image: circleci/python:3.7
-
-        working_directory: ~/repo
+  test-3.7: &test-template
+    docker:
+      - image: circleci/python:3.7
+    working_directory: ~/repo
+    steps:
+    - checkout
+    - restore_cache:
+        keys:
+            - v1-dependencies-{{ checksum "requirements.txt" }}
+            # fallback to using the latest cache if no exact match is found
+            - v1-dependencies-
+    - run:
+      name: install dependencies
+      command: |
+        python3 -m venv venv
+        . venv/bin/activate
+        pip install -e .
 
-        steps:
-            - checkout
+    - save_cache:
+      paths:
+        - ./venv
+      key: v1-dependencies-{{ checksum "requirements.txt" }}
 
-            # Download and cache dependencies
-            - restore_cache:
-                keys:
-                    - v1-dependencies-{{ checksum "requirements.txt" }}
-                    # fallback to using the latest cache if no exact match is found
-                    - v1-dependencies-
+    - run:
+      name: run tests
+      command: |
+        . venv/bin/activate
+        pip install codecov
+        pip install coverage
+        pip install opencv-python
+        pip install pytest
+        pip install scikit-image
+        coverage run -m pytest tests
+        codecov
 
-            - run:
-                name: install dependencies
-                command: |
-                    python3 -m venv venv
-                    . venv/bin/activate
-                    pip install -e .
+      # store artifacts (for example logs, binaries, etc)
+      # to be available in the web app or through the API
+      - store_artifacts:
+        path: test-reports
 
-            - save_cache:
-                paths:
-                    - ./venv
-                key: v1-dependencies-{{ checksum "requirements.txt" }}
+  test-3.6:
+    <<: *test-template
+    docker:
+      - image: circleci/python:3.6
 
-            # run tests with tox
-            - run:
-                name: run tests
-                command: |
-                    . venv/bin/activate
-                    pip install codecov
-                    pip install coverage
-                    pip install opencv-python
-                    pip install pytest
-                    pip install scikit-image
-                    coverage run -m pytest tests
-                    codecov
-#                    tox
-
-            # store artifacts (for example logs, binaries, etc)
-            # to be available in the web app or through the API
-            - store_artifacts:
-                path: test-reports
+#
+## Python CircleCI 2.0 configuration file
+##
+## Check https://circleci.com/docs/2.0/language-python/ for more details
+##
+#jobs:
+#    build:
+#        docker:
+#            # specify the version you desire here
+#            # CircleCI maintains a library of pre-built images
+#            # documented at https://circleci.com/docs/2.0/circleci-images/
+#            - image: circleci/python:3.7
+#
+#        working_directory: ~/repo
+#
+#        steps:
+#            - checkout
+#
+#            # Download and cache dependencies
+#            - restore_cache:
+#                keys:
+#                    - v1-dependencies-{{ checksum "requirements.txt" }}
+#                    # fallback to using the latest cache if no exact match is found
+#                    - v1-dependencies-
+#
+#            - run:
+#                name: install dependencies
+#                command: |
+#                    python3 -m venv venv
+#                    . venv/bin/activate
+#                    pip install -e .
+#
+#            - save_cache:
+#                paths:
+#                    - ./venv
+#                key: v1-dependencies-{{ checksum "requirements.txt" }}
+#
+#            - run:
+#                name: run tests
+#                command: |
+#                    . venv/bin/activate
+#                    pip install codecov
+#                    pip install coverage
+#                    pip install opencv-python
+#                    pip install pytest
+#                    pip install scikit-image
+#                    coverage run -m pytest tests
+#                    codecov
+#
+#            # store artifacts (for example logs, binaries, etc)
+#            # to be available in the web app or through the API
+#            - store_artifacts:
+#                path: test-reports