Added bandit to the build matrix.

.travis.yml

@@ -42,6 +42,9 @@ matrix:
   - python: '3.5'
     env: TOXENV=configcheck
     stage: lint
+  - python: '3.5'
+    env: TOXENV=bandit
+    stage: lint
   - python: '3.5'
     env: TOXENV=pydocstyle
     stage: lint