Implemented team update method

models/team_members_create.go

@@ -0,0 +1,8 @@
+package models
+
+// Create implements the create method to assign a user to a team
+func (tm *TeamMember) Create(doer *User, id int64) (err error) {
+	tm.TeamID = id
+	_, err = x.Insert(tm)
+	return
+}