endpoint mapping by http method

[hauner]

currently the endpoint mappings are applied to all http methods of a single endpoint:

openapi-processor-mapping: v2.0
    
map:
  paths:
    /foo:
      parameters:
        - add: request => javax.servlet.http.HttpServletRequest

It should be possible to configure an endpoint mapping only for a specific http method:

openapi-processor-mapping: v2.0
    
map:
  paths:
    /foo:
      get:
        parameters:
          - add: request => javax.servlet.http.HttpServletRequest

[hauner]

see #55