Streamlined API

I believe the API could be streamlined to support the common use cause of a business that wants to start receiving payments. ie

//Final implementation
Daraja daraja = new Daraja.Builder() //could be injected or single instanced
                 .setConsumerKey("")
                  .setConsumerSecrtet("")
                    .setCallbackUrl("")
                    .setBusinessShortCode("")
                    .setAccountType(TransactionType.CustomerBuyGoodsOnline)
                    .setParty(""); //not sure if partyA or partyB

//simpler API requests that returns the DarajaListener
daraja.pay("phone", "amount", "description"); //creates an LNMExpress class from Daraja and does api request

Currently, LNMExpress class holds to much scope, some of which should be held in the Daraja class.

I am willing to create a PR to demonstrate the same

[jumaallan]

@gilokimu

I might have an idea we can look at. Do you see how Firebase works, i.e the Cloud Messaging or Remote Config for example, Firebase is able to get your device regardless of the connected network you are connected to. The way I see it, its like they have a way to ping your device i.e in a callback way. If we are able to look at this, we could make the whole SDK work in the Android SDK. Let me get in touch with you actually, but we can move on with the discussion here

[jumaallan]

Closing this issue, for being stale for a while now 😶‍🌫️