no work filter

[atitoff]

Hi!
install ok

alex@orangepipcplus:~$ sudo -H  pip3.7 install cysystemd
Collecting cysystemd
  Downloading https://files.pythonhosted.org/packages/b7/64/9ab14a4682c39a5be35d99743f86a9d1b0c8955217bb7957d6af910e880a/cysystemd-1.1.0.tar.gz (193kB)
    100% |████████████████████████████████| 194kB 1.5MB/s
Installing collected packages: cysystemd
  Running setup.py install for cysystemd ... done
Successfully installed cysystemd-1.1.0

Example "Polling records" works fine.
"Read only cron logs" with errors:

Traceback (most recent call last):
  File "/home/alex/CSH/tests/journal.py", line 10, in <module>
    cron_reader.add_filter(rules)
  File "cysystemd/reader.pyx", line 489, in cysystemd.reader.JournalReader.add_filter
  File "cysystemd/reader.pyx", line 122, in __iter__
  File "cysystemd/reader.pyx", line 134, in cysystemd.reader.check_error_code
SystemError: ('Invalid argument', 'EINVAL')

Process finished with exit code 1

[mosquito]

Oh it's my mistake. Journal should be opened before adding filter rules.

[mosquito]

Readme was fixed.