Use current version of .travis.yml

Author: thebaer

.travis.yml

@@ -17,22 +17,8 @@ addons:
     packages:
       - libstdc++-5-dev
 
-cache:
-  directories:
-    - /tmp/liftoff
-
-matrix:
-  include:
-    - env: DIST=loki
-    - env: DIST=juno
-
 install:
-  - npm install @elementaryos/houston
+  - npm i -g @elementaryos/houston
 
 script:
   - houston ci
-    --distribution $DIST
-
-branches:
-  only:
-    - master