Prevent users from nulling out profile values (#1125)

* Prevent users from nulling out profile values

tests/api/v1/test_teams.py

@@ -379,6 +379,14 @@ def test_api_team_patch_me_logged_in_admin_captain():
 
         app.db.session.commit()
         with login_as_user(app, name="admin") as client:
+            # Users can't null out their team name
+            r = client.patch(
+                "/api/v1/teams/me", json={"name": None}
+            )
+            resp = r.get_json()
+            assert r.status_code == 400
+            assert resp["errors"]["name"] == ["Field may not be null."]
+
             r = client.patch(
                 "/api/v1/teams/me", json={"name": "team_name", "affiliation": "changed"}
             )