Merge pull request #91 from wangnuannuan/feature/travis

travis: when pull request and files in folder .ci not changed, build with ci files in master branch

Author: Wayne Ren

.travis.yml

@@ -37,10 +37,17 @@ branches:
     - gh-pages
 
 before_install:
-  - bash .ci/before_install.sh
   # setup git config 
   - git config --global user.name "embARC Automated Bot"
   - git config --global user.email "[email protected]"
+  - >
+    if [ "$TRAVIS_PULL_REQUEST" != "false" ]; then
+      diff=$(git diff FETCH_HEAD master .ci)
+      if [ "$diff" == "" ]; then
+        git checkout remotes/origin/master -- .ci
+      fi
+    fi
+  - bash .ci/before_install.sh
 
 after_success:
   - bash -c "$STATUS" success "Local $NAME testing has passed"