Adapte to 'nightly' tagged builds. (#92)

Author: falkzoll

tools/travis/build.sh

@@ -14,12 +14,12 @@ export OPENWHISK_HOME=$WHISKDIR
 cd $WHISKDIR
 
 # Pull down images
-docker pull openwhisk/controller
-docker tag openwhisk/controller ${IMAGE_PREFIX}/controller
-docker pull openwhisk/invoker
-docker tag openwhisk/invoker ${IMAGE_PREFIX}/invoker
-docker pull openwhisk/nodejs6action
-docker tag openwhisk/nodejs6action nodejs6action
+docker pull openwhisk/controller:nightly
+docker tag openwhisk/controller:nightly ${IMAGE_PREFIX}/controller
+docker pull openwhisk/invoker:nightly
+docker tag openwhisk/invoker:nightly ${IMAGE_PREFIX}/invoker
+docker pull openwhisk/nodejs6action:nightly
+docker tag openwhisk/nodejs6action:nightly nodejs6action
 docker pull openwhisk/python2action
 docker tag openwhisk/python2action python2action