Add support for S3 external upload

Add a flag (allowS3UploadedPayload ) to exchangeCode requests that indicate that the client supports using Amazon S3 upload for large payloads.

Basic Proxy Support

Summary

Proxy support added. Just include the full url to the config when instantiating. This does not include authorization for a proxy yet.

Example:

const civicClient = civicSip.newClient({
    appId: 'ABC123',
    appSecret: APP_SECRET,
    prvKey: PRV_KEY,
    proxy: {
        url: 'http://10.0.0.50:8080',
        rejectUnauthorized: false, // Do not use in production
    },
});

PRs

#31 Added chai as promised to dev dependancies
#32 Proxy support
#34 Proxy update
#35 Updated the version
#36 Security

Payload handling

Summary

Can request the sip-hosted-api endpoints to do payload processing via s3. This is to cater for larger payloads where lambdas have a limit of 6MB

Fixes

#27 Payload handling processor

v1.0.0

New Features

• removed babel and set minimum node version to 6.10.x
• removed legacy custom networking libs, now using needle
• eslint added to project
• improved readme.md example

v0.4.4

Bugfixes

• added safety checks when an error is thrown in exchangeCode (0b4e456)

v0.4.3

Bugfixes

• Replaced babel-pollyfill with babel-runtime to prevent polluting the globals such as Promise at top level applications. (90c5b5a)