readme: status for master branch

README.md

 # Knot DNS Resolver
 
-[![Build Status](https://img.shields.io/travis/CZ-NIC/knot-resolver.svg)](https://travis-ci.org/CZ-NIC/knot-resolver)
+[![Build Status](https://img.shields.io/travis/CZ-NIC/knot-resolver/master.svg)](https://travis-ci.org/CZ-NIC/knot-resolver)
 [![Coverage Status](https://img.shields.io/coveralls/CZ-NIC/knot-resolver.svg)](https://coveralls.io/r/CZ-NIC/knot-resolver)
 [![Coverity](https://img.shields.io/coverity/scan/3912.svg)](https://scan.coverity.com/projects/3912)
 [![Documentation Status](https://readthedocs.org/projects/knot-resolver/badge/?version=latest)](https://readthedocs.org/projects/knot-resolver/?badge=latest)
@@ -42,4 +42,4 @@ $ ./daemon/kresolved [working_directory]
 See the documentation at [knot-resolver.readthedocs.org][doc].
 
 [depends]: http://knot-resolver.readthedocs.org/en/latest/build.html
-[doc]: http://knot-resolver.readthedocs.org/en/latest/index.html
+[doc]: http://knot-resolver.readthedocs.org/en/latest/index.html
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