Update travis config

.travis.yml

@@ -1,11 +1,15 @@
 language: go
 go:
-  - 1.7
+  - 1.7.3
+before_install:
+  - go get github.com/kardianos/govendor
+script:
+  - govendor test +local +program
 after_success:
   - if [ "$TRAVIS_PULL_REQUEST" == "false" ]; then
     docker login -e $DOCKERHUB_EMAIL -u $DOCKERHUB_USER -p $DOCKERHUB_PASS;
     export REPO=jimeh/ozu.io;
-    export TAG=`if [ "$TRAVIS_BRANCH" == "master" ]; then echo "latest"; else echo $TRAVIS_BRANCH ; fi`;
+    export TAG="$(if [ "$TRAVIS_BRANCH" == "master" ]; then echo "latest"; else echo $TRAVIS_BRANCH ; fi)";
     make bin/ozuio_linux_amd64
     docker build -f Dockerfile -t $REPO:$TAG .
     docker push $REPO