Comment out Gittip link on gem pages

We don't yet have the landing pages on the Gittip side needed to support
the level of indirection to show Gittip accounts associated with a Ruby
gem:

    https://github.com/gittip/www.gittip.com/issues/1591

This comments out the link from gem pages for now. The link from
profile pages on Rubygems to Gittip is fine.
ruby_version is saved in versions
Issue #617 Ruby Dependency on rubygem show page
add ruby version unit tests
remove old rake task to update version
since we're not using it anymore
(see: https://github.com/rubygems/rubygems.org/pull/629#issuecomment-29638957)
Fix link to Travis CI in README.md

Seems like the old link with the anchor is not working.

The correct link is https://travis-ci.org/rubygems/rubygems.org
Merge pull request #632 from claudiob/patch-1

Fix link to Travis CI in README.md
Keep a consistent sans-serif font

This pull request is very font-nerdy :books: but here it goes.

One line of CSS specifies that Arial should be used over Helvetica, when possible. The other line of CSS specifies that Helvetica should be used over Arial, when possible. For visual consistency, the two lines should be the same.

And indeed, there is no need to specify either of those options, since `font-family: sans-serif` [already makes that choice for you](http://css-tricks.com/sans-serif), defaulting to Helvetica on Mac (where it's available) and to Arial on Windows.
Merge pull request #633 from claudiob/patch-2

Keep a consistent sans-serif font
Fix tests to reflect removal of download graphs

See ea0b13629f7c926637f8d819088f727dd9fcdd9e.
Pull the rubygems version from the gem db
Fix contribution guidelines link in README

It was pointing to the wiki and the wiki in turn points to CONTRIBUTING.md.
Merge pull request #640 from fphilipe/patch-1

Fix contribution guidelines link in README
Merge pull request #612 from whit537/unlink-gittip

Comment out Gittip link on gem pages
deploy via capistrano!
Merge pull request #642 from dwradcliffe/capistrano

deploy via capistrano!
Update nokogiri dependency to version 1.6.1
CVE 2013-6461
Merge pull request #643 from dwradcliffe/update-nokogiri

Update nokogiri dependency to version 1.6.1
remove old bluepill stuff
Merge pull request #646 from dwradcliffe/cleanup-bluepill

remove old bluepill stuff