Travis

`18:59:58 < Mikaela> FlashCode: I made a .travis.yml for WeeChat that just runs cmake and make and make install. Should I send a pull request? It looks like this https://github.com/Mkaysi/weechat/blob/travis/.travis.yml and results https://travis-ci.org/Mkaysi/weechat .`

`19:04:28  * Mikaela must go now, but she will open pull request in case it's wanted. It can always be closed without merging or used for base for proper travis.yml which has tests.`

I also added Travis buid status to README.asciidoc.

BEFORE MERGING (in case this is going to be merged): please go to https://travis-ci.org/profile and enable Travis for weechat/weechat.