Improve student search heuristic

Stop the search if . is reached
Stop the search if more than one user is returned
In both cases interrupt script and exit

pwm

@@ -62,10 +62,9 @@ def emails_to_ids(emails: List[str], headers: Dict[str, str]) -> List[int]:
 
     for email in emails:
         # Dirty and hackish way that attempts to extract the username from the email.
-        # It's inefficient, but currently there is now way to reliably obtain
+        # It's inefficient, but currently there is no way to reliably obtain
         # the username from the email.
-        # TODO: new strategy:
-        # - stop when we reach the "." or when we get more than 1 result
+        # new strategy: - stop when we reach the "." or when we get more than 1 result
         # Example of tricky users:
         # pierre-louis.roden@etu.hesge.ch -> login AAI: pierrelo.roden
         # joel.ferreirapinto@etu.hesge.ch -> login AAI: joelfili.ferreira
@@ -76,11 +75,17 @@ def emails_to_ids(emails: List[str], headers: Dict[str, str]) -> List[int]:
             #print("Guessed username: ",username)
             user_requested = requests.get(BASE_API_URL + '/users', params={'search': username}, headers=headers).json()
 
-            if len(user_requested) == 0:
+            nb_users = len(user_requested)
+            if nb_users == 0:
                 #print('No user %s found, another try...' % email)
                 lastchar = username[-1]
                 username = username.rstrip(lastchar)
+                if username[-1] == '.':  # stop if we reach the . -> probably at least one wrong person match the first name
+                    break
                 continue
+            elif nb_users > 1:
+                print('Too many users found for email %s, aborting.' % email)
+                exit(1)
 
             #print(json.dumps(user_requested, indent=4))
             user_ids.append(user_requested[0]['id'])
@@ -118,7 +123,7 @@ def create_repository(token: str, group_id: str, emails: List[str], name: str, i
     # Get students ids from their emails
     user_ids = emails_to_ids(emails, headers)
 
-    # Add each student as project's developer (level 30)
+    # Add each student as maintainer (level 40)
     for user_id in user_ids:
         params = {'user_id': user_id, 'access_level': access_level}
         if expires_at: