Fix reporting to coveralls

commit 22ebf99
Author: Michael Kühnel <[email protected]>
Date:   Mon Nov 21 23:17:14 2016 +0100

    Replace yarn run with npm run

commit d57f4fd
Author: Michael Kühnel <[email protected]>
Date:   Mon Nov 21 23:14:24 2016 +0100

    Fix reporting to coveralls

Author: mischah

.travis.yml

@@ -8,3 +8,5 @@ cache:
   yarn: true
   directories:
     - node_modules
+after_success:
+  - npm run coveralls