Only clear output directory content

Prevents file listing from jumping in editors.

Author: Siilwyn

package.json

@@ -90,7 +90,7 @@
     "url": "https://github.com/declandewet/common-tags"
   },
   "scripts": {
-    "clear": "rimraf lib && rimraf es && rimraf dist",
+    "clear": "rimraf lib/* && rimraf es/* && rimraf dist/*",
     "build": "npm run clear && npm run build:cjs && npm run build:es && npm run build:unpkg",
     "build:cjs": "babel src --out-dir lib --ignore **/*.test.js",
     "build:es": "cross-env BABEL_ENV=es babel src --out-dir es --ignore **/*.test.js",