Added the original gearmand to travis for testing:

1. It's easier to test with (it installs in the regular path), we need to start and stop it for network error tests
2. Can't hurt to test with both implementations!

.travis.yml

@@ -5,3 +5,4 @@ go:
 before_install:
   - sudo apt-get remove -y gearman-job-server
   - sudo apt-get install -y gearman-job-server
+  - sudo apt-get install -y gearman-server