fix: avoid adding every Mongoose instance to global driver

Author: vkarpov15

lib/driver.js

@@ -6,20 +6,10 @@
 
 let driver = null;
 
-const _mongooseInstances = [];
-module.exports._mongooseInstances = _mongooseInstances;
-
 module.exports.get = function() {
   return driver;
 };
 
 module.exports.set = function(v) {
   driver = v;
-
-  for (const mongoose of _mongooseInstances) {
-    const Connection = driver.getConnection();
-    mongoose.Connection = Connection;
-    mongoose.connections = [new Connection(mongoose)];
-    mongoose.Collection = driver.Collection;
-  }
 };

lib/index.js

@@ -70,7 +70,6 @@ function Mongoose(options) {
   }, options);
   const conn = this.createConnection(); // default connection
   conn.models = this.models;
-  driver._mongooseInstances.push(this);
 
   if (this.options.pluralization) {
     this._pluralize = legacyPluralize;