Move to yarn and volta

Author: kristoferbaxter

package.json

@@ -49,6 +49,7 @@
     "husky": "3.1.0",
     "lint-staged": "9.4.3",
     "np": "5.1.3",
+    "npm-run-all": "4.1.5",
     "prettier": "1.19.1",
     "rimraf": "3.0.0",
     "rollup": "0.67.4",
@@ -74,5 +75,9 @@
       "test/**/*.test.js"
     ],
     "verbose": true
+  },
+  "volta": {
+    "node": "12.13.1",
+    "yarn": "1.21.0"
   }
 }