Add appsettings config load for tests

Enables the config to be changed outside of the test
appsettings.local.json is not checked into the repo

test/AspNetCore.Identity.MongoDbCore.IntegrationTests/appsettings.json

@@ -0,0 +1,12 @@
+{
+  "MongoDbSettings": {
+    "ConnectionString": "mongodb://localhost:27017",
+    "DatabaseName": "MongoDbTests"
+  },
+  "Logging": {
+    "IncludeScopes": false,
+    "LogLevel": {
+      "Default": "Warning"
+    }
+  }
+}