let apns support multi-cert

[lbeeon]

I modified sort of the code, let the ios could support multiple certifications. The usage was same as the andriod platform. Make a request as followed

{
  "notifications": [
    {
      "tokens": ["token_a", "token_b"],
      "platform": 1,
      "message": "Hello World iOS!",
      "apns_client": "cert1",
    }
  ]
}

key "apns_client" will find the source from config.yaml. Certificaton can set in config.yaml as followed

ios:
  key_map:
    cert1: "key.pem"
    cert2: "cert2.pem"
    cert3: "cert3.pem"
  key_password:
    cert1: ""
    cert2: ""
    cert3: ""

#99

[janekolszak]

Hi! What's up with this change?

[kemotes]

Yeah, it would be good to have this change. The alternative is to setup 2 or more GoRush instances.

[itsnotvalid]

Totally agreed to support multiple certs and multiple API keys.

[mxpv]

I would suggest

ios:
  keys:
  - cert: "key.pem"
    password: ""
  - cert: "cert2.pem"
    password: ""
  - cert: "cert3.pem"
    password: ""

intead of

ios:
  key_map:
    cert1: "key.pem"
    cert2: "cert2.pem"
    cert3: "cert3.pem"
  key_password:
    cert1: ""
    cert2: ""
    cert3: ""

[Struik]

@appleboy Hey there Is there any chance this will be merged or any other way of supporting multiple apns certificated will be implemented?