fix: Lock esm to 3.0.28 to prevent error at build time

Latest releases of esm seem to cause errors at build time (TypeError: Cannot read property 'options'
of null), we'll lock the version to 3.0.28 for the moment

Fixes #85

package.json

@@ -43,7 +43,7 @@
   "dependencies": {
     "acorn": "^5.5.3",
     "cookie": "^0.3.1",
-    "esm": "^3.0.28",
+    "esm": "3.0.28",
     "fs": "^0.0.1-security",
     "vue-i18n": "^7.5.0",
     "vue-i18n-extensions": "^0.1.0"

yarn.lock

@@ -2869,7 +2869,7 @@ eslint@^4.19.1:
     table "4.0.2"
     text-table "~0.2.0"
 
-esm@^3.0.28:
+esm@3.0.28, esm@^3.0.28:
   version "3.0.28"
   resolved "https://registry.yarnpkg.com/esm/-/esm-3.0.28.tgz#1b912958328eb1c40538e7d24ce6bf3638bb83df"