Configure travis to run check_release.py

Author: lukpueh

.travis.yml

@@ -0,0 +1,13 @@
+language: python
+
+git:
+  clone: false
+
+install:
+  - git clone --depth=50 https://github.com/${TRAVIS_REPO_SLUG}.git ${TRAVIS_REPO_SLUG}
+  - cd ${TRAVIS_REPO_SLUG}
+  - git fetch origin pull/${TRAVIS_PULL_REQUEST}/head:${TRAVIS_PULL_REQUEST_BRANCH}
+  - git checkout -qf ${TRAVIS_PULL_REQUEST_BRANCH}
+
+script:
+  - python check_release.py