Add -B flag in travis file (#144)

This disables the downloading progress of the mvn site command

Author: e-pettersson-ericsson

.travis.yml

@@ -32,7 +32,7 @@ after_script:
 
 before_deploy:
   - rm -rf docs
-  - mvn site
+  - mvn site -B
   - mvn clean
 
 deploy:
@@ -41,4 +41,4 @@ deploy:
   github-token: $GITHUB_TOKEN
   local_dir: docs/
   on:
-    branch: master
+    branch: master