+ Exposing serde_json to db-lib lyaer

This dep was already there but just being used (as we're using serde). Now we can use it at the db layer which makes neighbor struct creation easier
* Cargo locks are being updated to reflect new dependancy changes
These changes actually reduce the dependancy count overall
+ Adding a very simple table to hold all the neighbors that an instance may want to reference
At some point we may want to support vanity join urls and this would be a good place to reference those
There would also need to be a way for admins to add/edit/remove vanity urls but that's for another patch

json-api/migrations/2021-05-04-200859_neighbors/down.sql

@@ -0,0 +1 @@
+DROP TABLE `neighbors`;

json-api/migrations/2021-05-04-200859_neighbors/up.sql

@@ -0,0 +1,10 @@
+-- everything else is nullable due to 
+-- A) Flexibility
+-- B) They're part of optional features(such as the wsurl which not all servers may have)
+CREATE TABLE IF NOT EXISTS `neighbors`(
+	`url` VARCHAR(512) UNIQUE NOT NULL,
+	`wsurl` VARCHAR(512),
+	`name` VARCHAR(512) NOT NULL,
+	`description` VARCHAR(1024),
+	`tags` VARCHAR(1024)
+);