Axios 16 compat

[myabc]

Some additions to @teppeis's PR #3 (mostly to address this comment: https://github.com/nettofarah/axios-vcr/pull/3#issuecomment-327885163)

• support both older and newer versions of Axios.
• set up testing against various versions of Axios.

[soswow]

1. Why do we need to support older axios?
2. It's 0.17 already latest.

[soswow]

Using this branch and axios 16 I have a problem. jsonPaths do not match between request and response During request:

{
   "url":"https://launchlibrary.net/1.2/launch",
   "method":"get",
   "headers":{
      "common":{
         "Accept":"application/json, text/plain, */*"
      },
      "delete":{
      },
      "get":{
      },
      "head":{
      },
      "post":{
         "Content-Type":"application/x-www-form-urlencoded"
      },
      "put":{
         "Content-Type":"application/x-www-form-urlencoded"
      },
      "patch":{
         "Content-Type":"application/x-www-form-urlencoded"
      }
   }
}

And during response

{
   "url":"https://launchlibrary.net/1.2/launch",
   "method":"get",
   "headers":{
      "Accept":"application/json, text/plain, */*"
   }
}

[soswow]

also for some reason it doesn't take params parameter =\

[nettofarah]

@soswow I would prefer that the library is backward compatible. But I'm ok with issuing a new major release to only support newer versions of axios