refactor: use explicit mocha imports (#40)

Author: JustinBeckwith

generated,README.md,.eslintrc.yml/system-test/.eslintrc.yml

@@ -1,5 +1,3 @@
 ---
-env:
-  mocha: true
 rules:
   node/no-extraneous-require: off

generated,README.md,.eslintrc.yml/system-test/samples.js

@@ -16,6 +16,7 @@
 
 const path = require('path');
 const {assert} = require('chai');
+const {describe, it} = require('mocha');
 const cp = require('child_process');
 
 const execSync = cmd => cp.execSync(cmd, {encoding: 'utf-8'});