Initialize an instance of PubNub to invoke operations.
|publish_key||String - your publish key from your PubNub Admin Dashboard account|
|subscribe_key||String - your publish key from your PubNub Admin Dashboard account|
Subscribe to a channel(s) and provide a means to receive messages published to the channel(s).
|channel||String - channel name or comma-delimited list of channel names|
|message||function - the callback function that will receive messages published on the subscribe channels|
|connect||function - the callback function that will be called when the subscription to the channels is successful|
Publish a message to a channel which will be received by subscribers on that channel.
|channel||String - channel name on which to send the message|
|message||String - The message to publish on the channel. JSON format is recommended (do not stringify; use the JSON object)|