tests/formatting/test_formatter.py:241
  /home/altendky/pendulum/tests/formatting/test_formatter.py:241:
DeprecationWarning: invalid escape sequence \[
    assert f.format(d, "[YYYY] YYYY \[YYYY\]") == "YYYY 2016 [2016]"

tests/formatting/test_formatter.py:242
  /home/altendky/pendulum/tests/formatting/test_formatter.py:242:
DeprecationWarning: invalid escape sequence \D
    assert f.format(d, "\D D \\\D") == "D 28 \\28"

tests/datetime/test_from_format.py::test_from_format_with_escaped_elements
  /home/altendky/pendulum/pendulum/formatting/formatter.py:406:
DeprecationWarning: Flags not at the start of the expression
'(?P<YYYY>\\d{1,4}|\\d{' (truncated)
    if not re.match(pattern, time):

tests/datetime/test_from_format.py::test_from_format[Thursday 25th
December 1975 02:15:16 PM -05:00-dddd Do MMMM YYYY hh:mm:ss A
Z-1975-12-25T14:15:16-05:00-None]
  /home/altendky/pendulum/pendulum/formatting/formatter.py:406:
DeprecationWarning: Flags not at the start of the expression
'(?P<dddd>Sunday|Mond' (truncated)
    if not re.match(pattern, time):

* Add RU locale

* Show "few seconds" as numbers, as in 1.x for RU locale

* Add RU locale tests

* Fix styling in locale.py