Add Travis badge to readme.
Add Travis badge to readme.

olafurpg/scalafmt,scalameta/scalafmt,Daxten/scalafmt,olafurpg/scalafmt,olafurpg/scalafmt,olafurpg/scalafmt,Daxten/scalafmt,scalameta/scalafmt,scalameta/scalafmt,scalameta/scalafmt