Travis: Checking that pin prevents updating

Author: ondrejfuhrer

.travis.yml

@@ -22,5 +22,8 @@ script:
   - brew cu pin java
   - brew cu pinned
   - brew cu -y --no-brew-update
+  - java --version > java.test.out && cat java.test.out | grep -q 13.
+  - rm -f java.test.out
   - brew cu unpin java
   - brew cu -y --no-brew-update
+  - java --version > test && cat test | grep -q 14.