feat: Team APIs (#1654)

Co-authored-by: Pranav Raj S <pranav@chatwoot.com>

db/migrate/20210114202310_create_teams.rb

@@ -0,0 +1,20 @@
+class CreateTeams < ActiveRecord::Migration[6.0]
+  def change
+    create_table :teams do |t|
+      t.string :name, null: false
+      t.text :description
+      t.boolean :allow_auto_assign, default: true
+      t.references :account, null: false, foreign_key: true
+
+      t.timestamps
+    end
+
+    create_table :team_members do |t|
+      t.references :team, null: false, foreign_key: true
+      t.references :user, null: false, foreign_key: true
+      t.timestamps
+    end
+
+    add_reference :conversations, :team, foreign_key: true
+  end
+end