fix: make @babel/runtime production dependencies (#461)

reference https://babeljs.io/docs/en/babel-runtime#usage

package.json

@@ -17,6 +17,7 @@
   "dependencies": {
     "@amplitude/ua-parser-js": "0.7.26",
     "@amplitude/utils": "^1.0.5",
+    "@babel/runtime": "^7.3.4",
     "blueimp-md5": "^2.10.0",
     "query-string": "5"
   },
@@ -27,7 +28,6 @@
     "@babel/plugin-proposal-object-rest-spread": "^7.3.4",
     "@babel/plugin-transform-runtime": "^7.3.4",
     "@babel/preset-env": "^7.3.4",
-    "@babel/runtime": "^7.3.4",
     "@semantic-release/changelog": "^5.0.1",
     "@semantic-release/exec": "^5.0.0",
     "@semantic-release/git": "^9.0.0",