Ignore .rdoc directory for tags
Add Verisign G5 CA cert and its intermediary

https://s3.amazonaws.com changed its certificate.  We did not have the
new root CA certificate (the G5 certificate) in our default certificate
list.

This caused connections to https://rubygems.org to fail for users who
did not have a full certificate list for openssl installed separately.

Now we have both the G5 certificate and its intermediary to allow
connections to succeed for users on cert.pem-less systems.

Fixes #665

Fixes #671
Remove redundent certs
Add #654 to history

Issue #654 removed redundant (useless) certificates that aren't needed
to connect to https://rubygems.org.  This was committed in @22e5981.

Fixes #654
Added a test for the included certificates
Mention #673 in History

Issue #673 adds a test for S3 and rubygems.org certificates to rubygems
so we can more quickly detect when a certificate's roots change.
Only run CA tests on travis-ci

The CA tests added in #673 run locally even when I don't have internet,
which can make the tests slower.

Now they'll only run on travis-ci which can take all the time it likes,
but will give similar value.
require should accept a Pathname object like Kernel#require
call to_path on the path before processing the path (if it responds to
to_path)
Add #663 to history
Add proper certificates for S3

Commit @71bc866 did not add the correct certificates as show by the test
from #673.  Now we have a tool to determine the correct certificates by
automatically from a certs.pem.

This updates #665 and #671.
Require rbconfig.rb for ConfigFile

On ruby 1.9.1 `gem -v` gives a NameError because RbConfig is not
available.

Now we require the missing file.

Fixes #676

See also wayneeseguin/rvm#2262
Correct History text #665 and #671

The description in the history was inaccurate following @82ed63e.
Remove unneeded require of rubygems/request

Issue #673 added a test for the bundled CA certificates which requires
rubygems/request, but the file is not used in the test.
Set release version and date