* Use golang's provided method names (gin)
This commit modifies the gin template for the router to leverage the http constants for method types as defined by RFC 7231 section 4.3. These are documented on:
https://golang.org/pkg/net/http/#pkg-constants
This removes the need for the `strings` dependency and does not require any new dependencies, as `net/http` is already imported.
* Remove strings dependency which is no longer used
* Update samples
* renmae Go post process file env variable
* add back samples/client/petstore/c/libcurl.licence
* keep go samples up-to-date
* update go petstore samples
* update go samples without formatting
* copy from go-server and add go-gin-server generator
* change the templates for the gin
* fix warnings of the golint tool
* fix the path of script
* add samples
* delete unnecessary comments (#1048)
* make the help message more appropriate (#1048)
* fix the link address format (#1048)
* minor improvement
