diff --git a/.gitignore b/.gitignore
index fd642e7..025ff01 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,10 @@
 /tmp
 /out-tsc
 
+#environments
+/src/environments/environment.ts
+/src/environments/environment.prod.ts
+
 # dependencies
 /node_modules
 
diff --git a/package-lock.json b/package-lock.json
index f76710d..79e57f9 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -3958,18 +3958,6 @@
         "is-directory": "^0.3.1",
         "js-yaml": "^3.13.1",
         "parse-json": "^4.0.0"
-      },
-      "dependencies": {
-        "js-yaml": {
-          "version": "3.13.1",
-          "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.13.1.tgz",
-          "integrity": "sha512-YfbcO7jXDdyj0DGxYVSlSeQNHbD7XPWvrVWeVUujrQEoZzWJIRrCPoyk6kL6IAjAG2IolMK4T0hNUe0HOUs5Jw==",
-          "dev": true,
-          "requires": {
-            "argparse": "^1.0.7",
-            "esprima": "^4.0.0"
-          }
-        }
       }
     },
     "create-ecdh": {
@@ -7442,21 +7430,13 @@
       "dev": true
     },
     "js-yaml": {
-      "version": "3.12.1",
-      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.12.1.tgz",
-      "integrity": "sha512-um46hB9wNOKlwkHgiuyEVAybXBjwFUV0Z/RaHJblRd9DXltue9FTYvzCr9ErQrK9Adz5MU4gHWVaNUfdmrC8qA==",
+      "version": "3.13.1",
+      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.13.1.tgz",
+      "integrity": "sha512-YfbcO7jXDdyj0DGxYVSlSeQNHbD7XPWvrVWeVUujrQEoZzWJIRrCPoyk6kL6IAjAG2IolMK4T0hNUe0HOUs5Jw==",
       "dev": true,
       "requires": {
         "argparse": "^1.0.7",
         "esprima": "^4.0.0"
-      },
-      "dependencies": {
-        "esprima": {
-          "version": "4.0.1",
-          "resolved": "https://registry.npmjs.org/esprima/-/esprima-4.0.1.tgz",
-          "integrity": "sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==",
-          "dev": true
-        }
       }
     },
     "jsbn": {
diff --git a/src/environments/environment_demo.ts b/src/environments/environment_demo.ts
new file mode 100644
index 0000000..ed2b9f1
--- /dev/null
+++ b/src/environments/environment_demo.ts
@@ -0,0 +1,23 @@
+// This file can be replaced during build by using the `fileReplacements` array.
+// `ng build ---prod` replaces `environment.ts` with `environment.prod.ts`.
+// The list of file replacements can be found in `angular.json`.
+
+export const environment = {
+  production: false,
+  firebase: {
+    apiKey: "",
+    authDomain: "",
+    databaseURL: "",
+    projectId: "",
+    storageBucket: "",
+    messagingSenderId: ""
+  }
+};
+
+/*
+ * In development mode, to ignore zone related error stack frames such as
+ * `zone.run`, `zoneDelegate.invokeTask` for easier debugging, you can
+ * import the following file, but please comment it out in production mode
+ * because it will have performance impact when throw error
+ */
+// import 'zone.js/dist/zone-error';  // Included with Angular CLI.