Speed up CI jobs

The CI jobs were unnecessarily executing "mvn test" a second time for
code coverage.
diff --git a/.travis.yml b/.travis.yml
index cedcd68..a35c311 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -37,7 +37,7 @@
  - mvn clean compile test -Dgpg.skip=true
 
 after_success: 
- - mvn clean test jacoco:report coveralls:report
+ - mvn jacoco:report coveralls:report
 
 notifications:
   email: false