[#3804] Fixed one failing spec for RackREST
A new version of Rack::MockRequest automatically uppercases the HTTP
method, expecting that any method passed in should properly be uppercase.
e.g. GET, PUT, POST
This behavior is on line 81 of Rack::MockRequest:
http://rack.rubyforge.org/doc/classes/Rack/MockRequest.src/M000230.html
Reviewed by Matt Robinson