Different Metacom interface for browser and server implementation

[muturgan]

The Metacom readme says:

// Open connection (both platforms) and make calls
const metacom = Metacom.create('https://domainname.com:8000');

But the server implementation does not contains a "create" static method. Its only possible to create a new Metacom instance via a "new" keyword.

[georgolden]

https://github.com/metarhia/metacom/pull/268

[georgolden]

I am not sure about this simple change. Interfaces are different even with current stage. I think we can make Websocket Transport optional for server-side client. And I think we need TCP support as well.