Added method to add a user to a team

REST-Tests/teams.http

@@ -0,0 +1,29 @@
+# Get all teams
+GET http://localhost:8080/api/v1/teams
+Authorization: Bearer {{auth_token}}
+
+###
+
+# Get one team
+GET http://localhost:8080/api/v1/teams/28
+Authorization: Bearer {{auth_token}}
+
+###
+
+# Add a new member to that team
+PUT http://localhost:8080/api/v1/teams/28/members
+Authorization: Bearer {{auth_token}}
+Content-Type: application/json
+
+{
+  "user_id": 2
+}
+
+###
+
+# Delete a member from a team
+DELETE http://localhost:8080/api/v1/teams/28/members/2
+Authorization: Bearer {{auth_token}}
+
+###
+