Update esm to the latest version 🚀 (#184)

* fix(package): update esm to version 3.0.20

* chore(package): update lockfile

https://npm.im/greenkeeper-lockfile

package-lock.json

@@ -3223,9 +3223,9 @@
       "dev": true
     },
     "esm": {
-      "version": "3.0.19",
-      "resolved": "https://registry.npmjs.org/esm/-/esm-3.0.19.tgz",
-      "integrity": "sha512-nzcyFclLSWL1zty9gW9RSkrhnl3LCJIoBC4rT9GRo6ws2kbaopWWt1DOa8QGQ4gqpbZPEoyCIrXhye8dmgIKmQ=="
+      "version": "3.0.20",
+      "resolved": "https://registry.npmjs.org/esm/-/esm-3.0.20.tgz",
+      "integrity": "sha512-r2XJJxPKoX7nu0dN56nH861b7Gw9+zQlY4Tw3jmWGnZzyzElHyNZ3K11u5aScAIC2DBOjUaHEaB/K0kSt1nFKQ=="
     },
     "espree": {
       "version": "3.5.4",

package.json

@@ -41,7 +41,7 @@
     "cross-env": "5.1.4",
     "css-loader": "0.28.11",
     "escape-html": "1.0.3",
-    "esm": "3.0.19",
+    "esm": "3.0.20",
     "events": "2.0.0",
     "express": "4.16.3",
     "fg-loadcss": "2.0.1",