chore: update braces and chokidar to latest versions (#3307)

This results in a significant dependencies reduction. New version of
chokidar also promises significant memory and performance improvements.

lib/watcher.js

@@ -12,7 +12,8 @@ const DIR_SEP = require('path').sep
 function watchPatterns (patterns, watcher) {
   let expandedPatterns = []
   patterns.map((pattern) => {
-    expandedPatterns = expandedPatterns.concat(braces.expand(pattern)) // expand ['a/{b,c}'] to ['a/b', 'a/c']
+    // expand ['a/{b,c}'] to ['a/b', 'a/c']
+    expandedPatterns = expandedPatterns.concat(braces.expand(pattern, { keepEscaping: true }))
   })
   expandedPatterns
     .map(PatternUtils.getBaseDir)

package.json

@@ -384,8 +384,8 @@
   "dependencies": {
     "bluebird": "^3.3.0",
     "body-parser": "^1.16.1",
-    "braces": "^2.3.2",
-    "chokidar": "^2.0.3",
+    "braces": "^3.0.2",
+    "chokidar": "^3.0.0",
     "colors": "^1.1.0",
     "connect": "^3.6.0",
     "core-js": "^2.2.0",