Replace constant instead of redefining it so that we don't get an ugly warning. Thanks @skade https://github.com/padrino/padrino-framework/pull/1181#issuecomment-15458360.
Using %[] as @DAddYE suggested.
Merge pull request #1187 from padrino/comply-to-sinatra-supported-http-verbs

Fix warning message on VALID_HTTP_VERBS