travis: remove dead code

.travis.yml

@@ -1,5 +1,4 @@
-# Force OS X.
+language: ruby
-language: objective-c
 os: osx
 env: OSX=10.11
 osx_image: xcode7.3
@@ -17,13 +16,6 @@ before_install:
     fi
   - git reset --hard $TRAVIS_COMMIT
   - git clean -qxdff
-
-install:
-  - if [ "$HOMEBREW_RUBY" = "1.8.7" ]; then
-      brew install homebrew/versions/ruby187;
-      export HOMEBREW_RUBY_PATH="/usr/local/opt/ruby187/bin/ruby";
-      brew untap homebrew/versions;
-    fi
   - export HOMEBREW_DEVELOPER="1"
   - ulimit -n 1024