Use ubuntu keyserver instead of mit (due to timeout)

Author: jimschubert

.travis.yml

@@ -78,7 +78,7 @@ before_install:
   # show java version
   - java -version
   - openssl aes-256-cbc -K $encrypted_6e2c8bba47c6_key -iv $encrypted_6e2c8bba47c6_iv -in sec.gpg.enc -out sec.gpg -d
-  - gpg --keyserver pgp.mit.edu --recv-key $SIGNING_KEY
+  - gpg --keyserver keyserver.ubuntu.com --recv-key $SIGNING_KEY
 
 install:
   # Add Godeps dependencies to GOPATH and PATH