[CI] build non-master branches (#8)

* travis: allow building non-master branches

Also add branch info to tag.

* fixup! travis: allow building non-master branches

Tag deploy with PR's branch if available

* squash! fixup! travis: allow building non-master branches

* retrigger build to see tag

* fixup! retrigger build to see tag

.travis.yml

@@ -37,14 +37,10 @@ before_cache:
   # Travis can't cache files that are not readable by "others"
   - chmod -R a+r $HOME/.cargo
 
-branches:
-  only:
-    - master
-
 before_deploy:
   - git config --local user.name "Andreas Heider"
   - git config --local user.email "[email protected]"
-  - git tag "$(date +'%Y-%m-%d')-$TRAVIS_BUILD_NUMBER-$(git log --format=%h -1)"
+  - git tag "$(date +'%Y-%m-%d')-$TRAVIS_BUILD_NUMBER-${TRAVIS_PULL_REQUEST_BRANCH:-$TRAVIS_BRANCH}-$(git log --format=%h -1)"
 
 deploy:
   provider: releases