suppress deprecation warning

```
tests/euci_test.py::test_get_string
  /home/stepan/project/pyuci/euci/__init__.py:34: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated since Python 3.3, and in 3.9 it will stop working
    return isinstance(data, collections.Iterable) and not isinstance(data, str)
```
1 job for python-3.9 in 17 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #423096
unittests

00:00:17