Refactor Socket Connection

This is a major release with breaking changes that include:

• An architecture change that creates a separate WebSocket connection for each instance of the SDK that is running in the same client and ensures completely separate state between instances
• Removal of the clientIndex parameter from the API and also removing it from calls to account, transaction and unsubscribe for a better dev experience.

Changes you need to make when upgrading from 1.x.x to 2.0.0:

• The SDK is now created from a class instead of a function, requiring the new keyword when instantiating:

// 1.x.x
import blocknativeSdk from 'bnc-sdk'
const blocknative = blocknativeSdk(options)

// 2.0.0
import BlocknativeSdk from 'bnc-sdk'
const blocknative = new BlocknativeSdk(options)

• The clientIndex parameter has been removed from the API and doesn't need to be included in function calls:

// === watching a transaction === //
// 1.x.x
const { emitter } = blocknative.transaction(blocknative.clientIndex, hash)
// 2.0.0
const { emitter } = blocknative.transaction(hash)

// === watching a account === //
// 1.x.x
const { emitter } = blocknative.account(blocknative.clientIndex, address)
// 2.0.0
const { emitter } = blocknative.account(address)

// === unwatching a transaction === //
// 1.x.x
const { emitter } = blocknative.unsubscribe(blocknative.clientIndex, hash)
// 2.0.0
const { emitter } = blocknative.unsubscribe(hash)

// === unwatching a account === //
// 1.x.x
const { emitter } = blocknative.unsubscribe(blocknative.clientIndex, address)
// 2.0.0
const { emitter } = blocknative.unsubscribe(address)

Changelog:

• Feature: refactor connection (#46)
• Bump acorn from 5.7.3 to 5.7.4 (#44)