(env/refactor): split out webpack and browserify config

- split them into files instead of command-line args in package.json
  scripts
  - webpack has a config file ofc, but wanted to keep them consistent
    initially, so used command-line
    - decided to use the browserify API as its "config file"
      - this actually took a decent amount of research to figure out
        how to output to file (have to pipe to fs stream)

browserify.config.js

@@ -0,0 +1,7 @@
+const browserify = require('browserify')
+const fs = require('fs')
+
+browserify({
+  entries: './test-utils/browserify/_export-to-window.js',
+}).bundle()
+  .pipe(fs.createWriteStream('./build/browserify.bundle.js'))

package.json

@@ -41,8 +41,8 @@
     "test": "npm run clean && npm run browserify && npm run webpack && ava",
     "test:browserify": "npm run browserify && ava browserify.spec.js",
     "test:webpack": "npm run webpack && ava webpack.spec.js",
-    "browserify": "browserify test-utils/browserify/_export-to-window.js > build/browserify.bundle.js",
-    "webpack": "webpack test-utils/webpack/_export-to-window.js -o build/webpack.bundle.js --mode='development'",
+    "browserify": "node browserify.config.js",
+    "webpack": "webpack",
     "clean": "rm -rf build/ && mkdir build/"
   },
   "ava": {

webpack.config.js

@@ -0,0 +1,11 @@
+const path = require('path')
+
+module.exports = {
+  entry: './test-utils/webpack/_export-to-window.js',
+  output: {
+    path: path.join(__dirname, '/build/'),
+    filename: 'webpack.bundle.js'
+  },
+  // fast builds, build is only used for testing purposes
+  mode: 'development'
+}