[ci] Added checkcommit to travis build #20

Related to #20
Related to #23

.travis.yml

@@ -26,7 +26,6 @@ before_install:
   - pip install -U pip wheel setuptools
   - pip install --no-cache-dir -U -r requirements-test.txt
 
-# command to install requirements
 install:
   - pip install https://github.com/openwisp/openwisp-users/tarball/master
   - pip install $DJANGO
@@ -36,9 +35,16 @@ before_script:
   - ./runflake8
   - ./runisort
 
-# command to run tests, e.g. python setup.py test
 script:
   - coverage run --source=openwisp_utils runtests.py
+  - |
+    if [ "$TRAVIS_PULL_REQUEST" != "false" ]; then
+      # gets commit message of last commit before pull request merge
+      COMMIT_MESSAGE=$(git log --format=%B -n 1)
+      echo "Checking commit message:"
+      echo "$COMMIT_MESSAGE"
+      checkcommit --message "$COMMIT_MESSAGE"
+    fi
 
 after_success:
   coveralls