Support ChatWork OAuth

[sue445]

New Features

Perform ChatWork API with access token

require "chatwork"

ChatWork.access_token = "XXX"
ChatWork::Message.create(room_id: 1234, body: "Hello, ChatWork!")

Refresh access token with refresh token

require "chatwork"

ChatWork.client_id = "XXX"
ChatWork.client_secret = "XXX"
refresh_token = "XXX"
token = ChatWork::Token.refresh_access_token(refresh_token)
new_access_token = token["access_token"]

# Create message
ChatWork.access_token = new_access_token
ChatWork::Message.create(room_id: 1234, body: "Hello, ChatWork!")

Specification

See following

• http://blog-ja.chatwork.com/2017/11/api-openbeta.html (ja)
• http://developer.chatwork.com/ja/oauth.html (ja)
• http://download.chatwork.com/ChatWork_API_Documentation.pdf (en)

Note

I think this PR conflicts with #20. I will immediately resolve the conflict after you merge.

[sue445]

I rebase and pushed.

[asonas]

I rebase and pushed.

Great!! I'm always grateful for your help!