Added a branch condition to the deploy stage (#3)

* Initial code drop

* Added readme and .travis.yml

* Made docker org an env var.

* added a deploy phase

* Adjusted deploy phase

* Added on branches to deploy

* Removed unnecessary blank line

.travis.yml

@@ -4,5 +4,9 @@ os:
 services:
 - docker
 deploy:
+  on:
+    branches:
+      only:
+        - master
   provider: script
-  script: bash ./docker-build.sh
+  script: bash ./docker-build.sh