Do not let Travis notify chat.freenode.org#pulp

Done by popular request. From IRC:

    <bowlofeggs> i'm not sure how others feel about this, but i'd prefer us not to have travis writing things here int he channel
    <bowlofeggs> because it makes the channel appear to have activity, but it's really noise
    <bowlofeggs> and it also interleaves with conversation, which makes reading a little difficult
    <bowlofeggs> travis can comment on the PRs in question, which i think accomplishes the purpose
    <dkliban> bowlofeggs: i agree. ichimonji10, would you mind turning off the travis-ci commenting in the channel?

.travis.yml

@@ -17,5 +17,3 @@ script:
     - make package-clean
 after_success:
     coveralls
-notifications:
-    irc: "chat.freenode.net#pulp"