remove @firebase/app and @firebase/app-types from peerDependencies (#2082)

* remove firebase/app and firebase/app-types from peerDependencies

* make app-types a regular dependency to make admin sdk happy

* demote @firebase/app and app-types to devDeps

Author: Feiyang1

packages/database-types/package.json

@@ -10,7 +10,7 @@
   "files": [
     "index.d.ts"
   ],
-  "peerDependencies": {
+  "dependencies": {
     "@firebase/app-types": "0.x"
   },
   "repository": {

packages/database/package.json

@@ -22,8 +22,6 @@
   },
   "license": "Apache-2.0",
   "peerDependencies": {
-    "@firebase/app": "0.x",
-    "@firebase/app-types": "0.x"
   },
   "dependencies": {
     "@firebase/database-types": "0.4.2",
@@ -33,6 +31,8 @@
     "tslib": "1.10.0"
   },
   "devDependencies": {
+    "@firebase/app": "0.x",
+    "@firebase/app-types": "0.x",
     "@types/chai": "4.2.0",
     "@types/mocha": "5.2.7",
     "@types/node": "11.13.19",