Move all the build scripts into scripts/ folder, ES6ify more stuff

scripts/build_css.js

@@ -0,0 +1,61 @@
+/* eslint-disable no-console */
+const colors = require('colors/safe');
+const concat = require('concat-files');
+const glob = require('glob');
+
+let _currBuild = null;
+
+// if called directly, do the thing.
+if (process.argv[1].indexOf('build_css.js') > -1) {
+  buildCSS();
+} else {
+  module.exports = buildCSS;
+}
+
+
+function buildCSS() {
+  if (_currBuild) return _currBuild;
+
+  const START = '🏗   ' + colors.yellow('Building css...');
+  const END = '👍  ' + colors.green('css built');
+
+  console.log('');
+  console.log(START);
+  console.time(END);
+
+  return _currBuild =
+    Promise.resolve()
+      .then(() => doGlob('css/**/*.css'))
+      .then(files => doConcat(files, 'dist/iD.css'))
+      .then(() => {
+        console.timeEnd(END);
+        console.log('');
+        _currBuild = null;
+      })
+      .catch(err => {
+        console.error(err);
+        console.log('');
+        _currBuild = null;
+        process.exit(1);
+      });
+}
+
+
+function doGlob(pattern) {
+  return new Promise((resolve, reject) => {
+    glob(pattern, (err, files) => {
+      if (err) return reject(err);
+      resolve(files);
+    });
+  });
+}
+
+function doConcat(files, output) {
+  return new Promise((resolve, reject) => {
+    concat(files, output, (err) => {
+      if (err) return reject(err);
+      resolve();
+    });
+  });
+}
+