Add failing test for #1454
Fix #1454 by requiring package.el eagerly

Just adding "(require 'package)" to "el-get-elpa-package-directory"
fixes this bug, because by the time any elpa package is being installed
or fetched, package.el has to be available, so all we have to do is load
it if it hasn't already been loaded.
Don't overwrite existing "package-archives" value

Instead, we add the archives we want without blowing away any others.
Merge pull request #1455 from DarwinAwardWinner/elpa-bootstrap-fix

Fix #1454 by requiring package.el eagerly