Revert "Merge pull request #2602 from MikeMcQuaid/travis-ci-tweaks"

This reverts commit 8d948e4b0b55912c592d34cb5ea83c649b1f9d5e, reversing
changes made to 2372872974d1049c2beafe7dedb7f8f882502058.

.travis.yml

@@ -8,11 +8,9 @@ matrix:
       osx_image: xcode8.3
       rvm: system
     - os: linux
-      sudo: false
       rvm: 2.0.0
 
 before_install:
-  - rm -rf Library/Homebrew/vendor/bundle/
   - export GEM_HOME="$PWD/Library/Homebrew/vendor/ruby/2.0.0"
   - gem list --installed bundler || gem install bundler
   - export PATH="$GEM_HOME/bin:$PATH"

Library/Homebrew/dev-cmd/tap-new.rb

@@ -46,10 +46,9 @@ module Homebrew
     travis = <<-EOS.undent
       language: ruby
       os: osx
+      env: OSX=10.12
       osx_image: xcode8.3
       rvm: system
-      cache:
-        directories: /usr/local/Homebrew/Library/Homebrew/vendor
 
       before_install:
         - export TRAVIS_COMMIT="$(git rev-parse --verify -q HEAD)"