src: implement standard.js linting

In addition:

* moved module.exports to the bottom
* no single-line if statements
* no if statements without a {
* const for requires
* array declarations get spaces inside [ ]
* 'use strict' in all .js files

PR-URL: https://github.com/nodejs/node-gyp/pull/1794
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: João Reis <reis@janeasystems.com>

lib/find-visualstudio.js

@@ -1,8 +1,4 @@
-module.exports = exports = findVisualStudio
-module.exports.test = {
-  VisualStudioFinder: VisualStudioFinder,
-  findVisualStudio: findVisualStudio
-}
+'use strict'
 
 const log = require('npmlog')
 const execFile = require('child_process').execFile
@@ -132,9 +128,13 @@ VisualStudioFinder.prototype = {
     var ps = path.join(process.env.SystemRoot, 'System32',
       'WindowsPowerShell', 'v1.0', 'powershell.exe')
     var csFile = path.join(__dirname, 'Find-VisualStudio.cs')
-    var psArgs = ['-ExecutionPolicy', 'Unrestricted', '-NoProfile',
-      '-Command', '&{Add-Type -Path \'' + csFile + '\';' +
-      '[VisualStudioConfiguration.Main]::PrintJson()}']
+    var psArgs = [
+      '-ExecutionPolicy',
+      'Unrestricted',
+      '-NoProfile',
+      '-Command',
+      '&{Add-Type -Path \'' + csFile + '\';' + '[VisualStudioConfiguration.Main]::PrintJson()}'
+    ]
 
     this.log.silly('Running', ps, psArgs)
     var child = execFile(ps, psArgs, { encoding: 'utf8' },
@@ -188,7 +188,9 @@ VisualStudioFinder.prototype = {
 
     // Remove future versions or errors parsing version number
     vsInfo = vsInfo.filter((info) => {
-      if (info.versionYear) { return true }
+      if (info.versionYear) {
+        return true
+      }
       this.addLog(`unknown version "${info.version}" found at "${info.path}"`)
       return false
     })
@@ -415,3 +417,9 @@ VisualStudioFinder.prototype = {
     return true
   }
 }
+
+module.exports = findVisualStudio
+module.exports.test = {
+  VisualStudioFinder: VisualStudioFinder,
+  findVisualStudio: findVisualStudio
+}