[FIX] API tests with stubs for RippleRestClient and add them to the 'npm test' command
[FEATURE] incoming payment class

validate incoming payments, not require validation, replace process
with new class

[TEST] Incoming Payment class

[TASK] ignore coverage, add lodash
[FEATURE] Ripple Rest Error handler class

refactor outgoing_payment class to use the new Ripple Rest Error
handler class

[TEST] Ripple Rest Error Handler
[FEATURE] gatewayd.features for beta feature flags.
[FEATURE] incoming payment class

validate incoming payments, not require validation

[TEST] Incoming Payment class

[TASK] ignore coverage, add lodash
[FEATURE] use account monitor

Refactor processes/incoming.js and IncomingPayment Class to use Ripple
Account Monitor to listen to incoming payments GA-599. Also addresses
GA-616.

[FEATURE] Get/Set/Fetch Last payment hash

These set of features will addressing GA-616

[TASK] update cli to use updated API

[TEST] Incoming payment class,

[TEST] get/set/fetch last payment hash

[TASK] update account monitor to 2.2.0