build/*.js: set `sourceType` to module.

build/.eslintrc.json

@@ -4,7 +4,7 @@
     "node": true
   },
   "parserOptions": {
-    "sourceType": "script"
+    "sourceType": "module"
   },
   "extends": "../.eslintrc.json",
   "rules": {

build/build-plugins.js

@@ -5,8 +5,6 @@
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 
-'use strict'
-
 const rollup  = require('rollup')
 const path    = require('path')
 const babel   = require('rollup-plugin-babel')

build/change-version.js

@@ -7,8 +7,6 @@
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 
-'use strict'
-
 const fs = require('fs')
 const path = require('path')
 const sh = require('shelljs')

build/generate-sri.js

@@ -10,8 +10,6 @@
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 
-'use strict'
-
 const fs = require('fs')
 const path = require('path')
 const sriToolbox = require('sri-toolbox')

build/lint-vars.js

@@ -7,8 +7,6 @@
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 
-'use strict'
-
 const fs = require('fs')
 const path = require('path')
 const glob = require('glob')

build/postcss.config.js

-'use strict'
-
 module.exports = (ctx) => ({
   map: ctx.file.dirname.includes('examples') ? false : {
     inline: false,

build/rollup.config.js

-'use strict'
-
 const path    = require('path')
 const babel   = require('rollup-plugin-babel')
 const resolve = require('rollup-plugin-node-resolve')

build/saucelabs-unit-test.js

@@ -12,8 +12,6 @@ Win Opera 15+ is not currently supported by Sauce Labs
 iOS Chrome is not currently supported by Sauce Labs
 */
 
-'use strict'
-
 const path = require('path')
 const JSUnitSaucelabs = require('jsunitsaucelabs')
 

build/vnu-jar.js

@@ -7,8 +7,6 @@
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 
-'use strict'
-
 const childProcess = require('child_process')
 const vnu = require('vnu-jar')
 

build/workbox.js

@@ -5,8 +5,6 @@
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 
-'use strict'
-
 const fs = require('fs')
 const path = require('path')
 const swBuild = require('workbox-build')