Add async support

[tonybenoy]

Requests was replaced with httpx in the early days so as to enable the wrapper to call the APIs asynchronously. Although httpx was added the async capabilities were never added/implemented due to a lack of time and me being lazy overall.
In order to implement the same I would have to either

1. Add new methods i.e. async_
2. Add a wrapper that would make the function awaitable if needed
3. Add a new async class which would preferably inherit from CocApi and add async
   The main concern being that all methods are simply a wrapper around endpoints I really don't want to maintain twice the functions just to add async.