Update .travis.yml

Remove unused branch rule for travis.

.travis.yml

@@ -18,10 +18,6 @@ before_install:
   # install latest LCOV (1.9 was failing)
   - if [ "$TRAVIS_OS_NAME" = "linux" ]; then cd ${TRAVIS_BUILD_DIR} && wget http://ftp.de.debian.org/debian/pool/main/l/lcov/lcov_1.11.orig.tar.gz && tar xf lcov_1.11.orig.tar.gz && sudo make -C lcov-1.11/ install && gem install coveralls-lcov && lcov --version && g++ --version ; fi
 
-branches:
-  only:
-    - master
-
 os:
   - linux