Attempt to fix OpenDiablo2 deploy to master (#215)

* Remove on tag: true release
* Add configuration to release on master
* Add before_deploy step to tag build before release

.travis.yml

@@ -28,6 +28,9 @@ git:
   depth: 1
 notifications:
   email: false
+before_deploy:
+  - export TRAVIS_TAG=${TRAVIS_TAG:-$(date +'%Y%m%d%H%M%S')-$(git log --format=%h -1)}
+  - git tag $TRAVIS_TAG
 deploy:
   provider: releases
   api_key:
@@ -39,4 +42,4 @@ deploy:
   name: "OpenDiablo Unstable (Build $TRAVIS_BUILD_NUMBER)"
   prerelease: true
   on:
-    tags: true
+    branch: master