Update build badge to point to travis-ci.com

We now moved to travis-ci.com, so the badge needs to be updated
accordingly. I also realised the source of the badge was pointing to the
wrong repository, and has been since always.

Signed-off-by: Rodrigo Tobar <rtobar@icrar.org>

README.md

@@ -1,6 +1,6 @@
 # libprofit
 
-[![Travis Build Status](https://travis-ci.org/SKA-ScienceDataProcessor/dfms.svg?branch=master)](https://travis-ci.org/ICRAR/libprofit)
+[![Travis Build Status](https://travis-ci.com/ICRAR/libprofit.svg?branch=master)](https://travis-ci.com/ICRAR/libprofit)
 [![AppVeyor Build status](https://ci.appveyor.com/api/projects/status/mr42dlpq9vaeqnln?svg=true)](https://ci.appveyor.com/project/rtobar/libprofit)
 [![Coverage Status](https://coveralls.io/repos/github/ICRAR/libprofit/badge.svg?branch=master)](https://coveralls.io/github/ICRAR/libprofit?branch=master)
 [![Docs](https://readthedocs.org/projects/libprofit/badge/?version=latest)](https://libprofit.readthedocs.io/en/latest/)