Feature Flags client

NodeJS client grpc lib, for featureflags service. Provides abilitty to gracefull set and updates
for ur features.

> .proto files were taken directly from repo above.
> They should be uploaded in some place from the root repo on deploy i guess

API

FeatureClient is the base class. With it's constructor u will init grpc client, wich will call ExchangeRequest
every 5 min. in async manner. So it shouldn't hurt ur eventloop much, or app performance, coz of inmemory caching and time interval.

So u do this on application start:
``js
import { FeatureClient, Variable, Types } from '@evo/featureflags-client';

// Ur default flags dict
const Flags = {
TEST: false,
NODE: false
};

const featureClient = new FeatureClient(
'thecorp', // project name
'grpc:50051', // grpc-url
Flags, // default flags
[
new Variable('username', Types.STRING) // ur controll values for Checks
],
true, // isDebugg mode
);
`

In ur controllers, or somewhere when ur need ur features to work properly,
call getFlags, and provide there context = {}. Ctx is the object with Variable as a key,
and a value u want checks to depend on.

`js
import { getFlags } from '@evo/featureflags-client';

// ready to use object with proceeded checks
const flags = getFlags({ username: 'Petro' });

if (flags.TEST) doSomeThing();
``

$3

There several features, that exists in python flags.lib
, that u are free to extend:

- StatsController - Accumulates interval/flag/requests count
- Tracer - Accumulates request/flag/values