Travis ci update

Test on 2.1.1
Dont allow failures on 2.1.x
Merge pull request #1209 from arthurnn/travis_ci

Travis ci update
Prevent the file watcher from recursively enumerating into paths that it should ignore. This should fix the issue in #1197 as well as provide a performance boost when starting 'middleman server'.
Add tzinfo-data for Windows users
Merge pull request #1218 from bhollis/ignore

Prevent the file watcher from recursively enumerating into paths that it should ignore
Merge pull request #1219 from bhollis/windows

Add tzinfo-data for Windows users
upgrade to newest activesupport
add node_modules to filewatcher ignore
Don't attempt to load local templates if HOME is not set
Don't bother processing asset hash on ignored resources. On a large project with a lot of Sprockets dependencies that were mostly ignored, this brought the build down from 30 minutes to 1 minute
Ignore .cache by default in .gitignore
Improvements to the /__middleman/ metadata pages.

Includes formatting/styling changes to clarify the data being presented as well as align styling with middlemanapp.com. Also adds features and fixes to the sitemap view to show ignored files differently, hide redundant information, print data/options as a hash instead of as array pairs, and to list out available locals defined on a page.
Merge pull request #1229 from bhollis/metadata

Improvements to the /__middleman/ metadata pages
Webrick should not do reverse DNS lookups

This prevents Middleman server from being terribly slow over network. Closes #1118.
Merge pull request #1232 from lolmaus/patch-1

Webrick should not do reverse DNS lookups