Convert Network component to an ES6 class (#7784)

Co-authored-by: Mark Stacey <markjstacey@gmail.com>

ui/app/components/app/network.js

@@ -2,22 +2,25 @@ import PropTypes from 'prop-types'
 import React, { Component } from 'react'
 
 import classnames from 'classnames'
-import { inherits } from 'util'
 import NetworkDropdownIcon from './dropdowns/components/network-dropdown-icon'
 
-Network.contextTypes = {
+export default class Network extends Component {
+  static contextTypes = {
     t: PropTypes.func,
-}
+  }
 
-export default Network
+  static propTypes = {
+    network: PropTypes.string.isRequired,
+    provider: PropTypes.shape({
+      type: PropTypes.string,
+      nickname: PropTypes.string,
+      rpcTarget: PropTypes.string,
+    }).isRequired,
+    disabled: PropTypes.bool,
+    onClick: PropTypes.func.isRequired,
+  }
 
-inherits(Network, Component)
+  render () {
-
-function Network () {
-  Component.call(this)
-}
-
-Network.prototype.render = function Network () {
     const context = this.context
     const networkNumber = this.props.network
     let providerName, providerNick, providerUrl
@@ -173,4 +176,5 @@ Network.prototype.render = function Network () {
         })()}
       </div>
     )
+  }
 }