refactor: remove buffer shim

shims/buffer.js

@@ -1,7 +0,0 @@
-const { Buffer } = require('../src/index');
-
-module.exports = {
-  __esModule: true,
-  default: Buffer,
-  Buffer,
-};

tests/spec/shims/buffer.spec.js

@@ -1,23 +0,0 @@
-'use strict';
-const expect = require('chai').expect;
-const bufferDefault = require('../../../shims/buffer').default;
-const bufferNamed = require('../../../shims/buffer').Buffer;
-const bufferActual = require('../../../src/index').Buffer;
-
-describe('path shim', () => {
-  it('default export should be defined', () => {
-    expect(bufferDefault).to.not.be.undefined;
-  });
-
-  it('named export should be defined', () => {
-    expect(bufferNamed).to.not.be.undefined;
-  });
-
-  it('default export should be re-exposing Buffer', () => {
-    expect(bufferDefault).to.equal(bufferActual);
-  });
-
-  it('named export should be re-exposing Buffer', () => {
-    expect(bufferNamed).to.equal(bufferActual);
-  });
-});