Add initial test parameter plugin (HTTP method)
Fix method schema
Make use of method parameter plugin in web test
Add test for method plugin
Update README
Add headers parameter
Use headers test parameter in WebTest
Add test for HeadersTestParameter schema
Remove unused code
Add test for invalid parameter
Always load headers last to override any headers that might be set by
other plugins
Add header example to readme
Merge remote-tracking branch 'refs/remotes/origin/master' into add-parameter-plugins
Merge pull request #23 from sjagoe/add-parameter-plugins

Add parameter plugins