fix(trakt/username): restrict to alphanumeric usernames

addresses a bug that needs further investigation returning 405 when non-alphanumeric usernames are provided to trakt's api

#7

retraktarr/config.py

@@ -50,6 +50,19 @@ def __init__(self, config_file):
         else:
             try:
                 self.conf.read(config_file)
+                # checks for alphanumeric usernames
+                if (
+                    bool(
+                        re.compile(r"^[a-zA-Z0-9]+$").match(
+                            self.conf.get("Trakt", "username")
+                        )
+                    )
+                    is False
+                ):
+                    print(
+                        "Error occurred while reading the configuration file:\nOnly alphanumeric usernames are supported currently."
+                    )
+                    sys.exit(1)
             except configparser.Error as error:
                 print(f"Error occurred while reading the configuration file: {error}")
                 sys.exit(1)