MNT: Exit with a parser error from the CLI

If there is an error currently we print out a long stack trace. We
can change this to just print the error message through a parser
error rather than via the full stack trace when using this package
as a CLI utility.

imap_data_access/cli.py

@@ -291,7 +291,10 @@ def main():
 
     # Now process through the respective function for the invoked command
     # (set with set_defaults on the subparsers above)
-    args.func(args)
+    try:
+        args.func(args)
+    except Exception as e:
+        parser.error(e)
 
 
 if __name__ == "__main__":