Enable regular build on Travis?

[junaruga]

Can you enable regular automatic build on Travis for master branch?

Right now it looks not enabled.
https://travis-ci.org/jonleighton/spring-watcher-listen/branches

Because I faced below error on my pull-request: #16 .
I want to know current master branch's situation.

 1) Error:
AcceptanceTest#test_app_gets_reloaded_even_with_a_ton_of_boot_output:
Errno::EBADF: Bad file descriptor

As we are using latest master spring for the testing, I think that enabling it is useful.

https://github.com/jonleighton/spring-watcher-listen/blob/master/Gemfile#L6

[rafaelfranca]

Enabled now