Downgrade to regexpu-core 1.0

Author: Diogo Franco (Kovensky)

package.json

@@ -33,7 +33,7 @@
   "dependencies": {
     "cssesc": "^0.1.0",
     "fastparse": "^1.1.1",
-    "regexpu-core": "^3.2.0"
+    "regexpu-core": "^1.0.0"
   },
   "devDependencies": {
     "chokidar-cli": "^0.2.1",