Use 'double' instead of 'mock' about rspec-mock

'mock' is deprecated after rspec-mock 2.14.0.rc1(2013-05-27 released).
'mock' method may be removed for rspec-mock 3.0.0.

And, this fixes can remove following warnings.
DEPRECATION: mock is deprecated. Use double instead. Called from ...
Use 'stub' instead of 'stub!' about rspec-mock

'stub!' is deprecated after rspec-mock 2.14.0.rc1(2013-05-27 released).
'stub!' method may be removed for rspec-mock 3.0.0.

And, this fixes can remove following warnings.
DEPRECATION: stub! is deprecated. Use stub instead. Called from ...
Merge pull request #203 from co-me/unuse-deprecated-method

Stop using deprecated rspec-mock methods
Upped the minimum versions required for rspec and webmock

These were needing to be corrected even before the spec changes merged
today.
run test suite with warnings enabled
remove warning about unused variable and actually set message
remove warnings about URI.escape when available
convert == to eq to avoid warnings, (all were done for concistency)
actually assert in spec, and fix result
remove warning for unused var
cleanup trailing whitespace