change gcov to 5 as well.

Author: jacobwilliams

.travis.yml

@@ -56,7 +56,7 @@ install:
   - export FC=/usr/bin/gfortran-5
   - ln -fs /usr/bin/gfortran-5 "$HOME/.local/bin/gfortran" && gfortran --version
   - ls -l /usr/bin/gfortran-5
-  - ln -fs /usr/bin/gcov-4.9 "$HOME/.local/bin/gcov" && gcov --version
+  - ln -fs /usr/bin/gcov-5 "$HOME/.local/bin/gcov" && gcov --version
   - perl --version
   - |
     if ! which f90split; then