push develop branch as edge tag to docker hub

Author: appinteractive

.travis.yml

@@ -30,3 +30,7 @@ after_success:
     docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD";
     docker push humanconnection/api-feathers:alpha;
     fi
+  - if [ $TRAVIS_BRANCH == "develop" ] && [ $TRAVIS_EVENT_TYPE == "push" ]; then
+    docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD";
+    docker push humanconnection/api-feathers:edge;
+    fi