Fix web3 type definitions

Based on web3/web3.js#1658 (comment)

Author: dylanseago

package.json

@@ -22,7 +22,8 @@
     "build": "npm run lint && npm run build:webpack",
     "version": "git checkout develop && npm run build && git add -A dist",
     "postversion": "git push && git push --tags",
-    "release": "git checkout master && git merge develop && git push && git checkout develop"
+    "release": "git checkout master && git merge develop && git push && git checkout develop",
+    "postinstall": "rm -f node_modules/web3/index.d.ts"
   },
   "standard": {
     "ignore": [

src/services/Web3.ts

@@ -1,5 +1,5 @@
 import config from 'Config'
-import Web3 from 'web3'
+import Web3 = require('web3')
 
 declare global {
   interface Window {

src/utilities/convert.ts

@@ -81,7 +81,7 @@ export function toTxFee(gasLimit: Numerical, gasPrice: Numerical): BigNumber {
 
 export function toHex(value: Numerical): string {
   value = toBigNumber(value)
-  return web3.utils.numberToHex(value)
+  return web3.utils.toHex(value)
 }
 
 export function toChecksumAddress(address: string): string {