Fixes a adjustedment made to the YAML part of Ruby
Fixing errors reported by Travis

Should have run rake first before commiting -.- But now it passes!
See if we need this exception or not
Prepare 4.0.0.beta2 release
Better way to detect method present

Thanks to @sferik for the catch
Merge pull request #483 from davidakachaos/fix_yaml_error

Fixes a adjustedment made to the YAML part of Ruby
Documented the Delayed::Worker.default_queue_name option
Merge pull request #529 from brocktimus/master

Add default queue name to README
update some deprecated rspec methods
Merge pull request #540 from tiegz/spec_deps

Update some rspec methods that warn of deprecations.
Specs need to pass against rails 4 for a passing build
Stop testing against ruby 1.8

Ruby 1.8 has been EOL'ed and our build matrix is much bigger than it needs to be
Add more details to the contributing guide