Support form data

[goofmint]

Support form data boundary like this.

curl \'https://api.sloths.com\' -H \'Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryHKOJEwZFCnY9xIEy\' --data-binary $\'------WebKitFormBoundaryHKOJEwZFCnY9xIEy\r\nContent-Disposition: form-data; name="show"\r\n\r\n615727\r\n------WebKitFormBoundaryHKOJEwZFCnY9xIEy\r\nContent-Disposition: form-data; name="body"\r\n\r\nhello world!\r\n------WebKitFormBoundaryHKOJEwZFCnY9xIEy\r\nContent-Disposition: form-data; name="type"\r\n\r\n0\r\n------WebKitFormBoundaryHKOJEwZFCnY9xIEy\r\nContent-Disposition: form-data; name="icon"; filename="testorig.jpg"\r\nContent-Type: image/jpeg\r\n\r\n\r\n------WebKitFormBoundaryHKOJEwZFCnY9xIEy\r\nContent-Disposition: form-data; name="serviceId"\r\n\r\nAAA\r\n------WebKitFormBoundaryHKOJEwZFCnY9xIEy\r\nContent-Disposition: form-data; name="accessToken"\r\n\r\nBBB\r\n------WebKitFormBoundaryHKOJEwZFCnY9xIEy--\r\n\'

to

{
    method: "POST",
    header: {
      "Content-Type":"multipart/form-data; boundary=----WebKitFormBoundaryHKOJEwZFCnY9xIEy"
    },
    url: 'https://api.sloths.com',
    body: {
      show: "615727",
      body: "hello world!",
      type: 0,
      icon: {filename: "testorig.jpg"},
      serviceId: "AAA",
      accessToken: "BBB"
    }
}