Activate virtualenv correctly

Author: DarcyRaynerDD

.circleci/config.yml

@@ -20,18 +20,18 @@ jobs:
           command: |
             pip install virtualenv
             virtualenv venv
-            ./venv/bin/activate
+            source venv/bin/activate
             pip install -r requirements.txt
             pip install -r requirements-dev.txt
       - run:
           name: Run Unit Tests
           command: |
-            ./venv/bin/activate
+            source venv/bin/activate
             nose2 -v
       - run:
           name: Lint
           command: |
-            ./venv/bin/activate
+            source venv/bin/activate
             flake8 datadog_lambda/
 
       - save_cache: