Merge pull request #99 from zimmski/fix-travis.yml

YAML is pretty strict about indentations
diff --git a/.travis.yml b/.travis.yml
index b78cd52..6f2f220 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,3 +1,3 @@
 language: go
 after_success:
-	- coveralls
+  - coveralls