Cleanup imports from @polkadot/util (#315)

* Cleanup imports from @polkadot/util

* Example imports

* Alphabetic imports

packages/types/src/Metadata.spec.js

@@ -2,7 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the ISC license. See the LICENSE file for details.
 
-import hexToU8a from '@polkadot/util/hex/toU8a';
+import { hexToU8a } from '@polkadot/util';
 
 import Metadata from './Metadata';
 import rpcdata from './Metadata.rpc';

packages/types/src/Method.ts

@@ -2,9 +2,8 @@
 // This software may be modified and distributed under the terms
 // of the ISC license. See the LICENSE file for details.
 
-import assert from '@polkadot/util/assert';
 import { ExtrinsicFunction, Extrinsics } from '@polkadot/extrinsics/types';
-import { isHex, isObject, isU8a } from '@polkadot/util';
+import { assert, isHex, isObject, isU8a } from '@polkadot/util';
 
 import Base from './codec/Base';
 import { Constructor } from './types';

packages/types/src/scripts/MetadataMd.ts

@@ -2,8 +2,8 @@
 // This software may be modified and distributed under the terms
 // of the ISC license. See the LICENSE file for details.
 
-const fs = require('fs');
-import { stringCamelCase, stringLowerFirst } from '@polkadot/util/string';
+import fs from 'fs';
+import { stringCamelCase, stringLowerFirst } from '@polkadot/util';
 
 import interfaces from '../../../type-jsonrpc/src';
 import Metadata from '../Metadata';