get is forced upon all reqeusts by default, moved it to default options instead

[vasilevich]

when you perform
axiosinstance.request()
,
this line:
config = utils.merge(defaults, this.defaults, { method: 'get' }, config);
is forcing the "get" method upon ALL requests by default, unless you explicitly call
axiosinstance.request({method:'post'})
even tho in axios.create you set it to post/put/etc.
so I just moved method: 'get' to defaults.
it should be in the defaults anyway, rather than here.

how to reproduce the problem:

const axiosInstance = axios.create({
      baseURL: 'http://localhost',
      responseType: 'json',
       method: 'POST',
      withCredentials: true,
      validateStatus: function (status) {
        return status >= 200 && status < 300; // default
      },
    });
axiosInstance.request(); //the request will be 'GET' not 'POST'
axiosInstance.request({method:'POST'});  /the request will be 'POST' good.

[coveralls]

Coverage remained the same at 93.812% when pulling a622a30 on vasilevich:master into 07a7b7c on mzabriskie:master.

[chinesedfan]

Fixed by #2383. Thanks all the same.