tests: Fix CAS version parsing

As CAS version format changed to custom one, we need to parse it
in non-default way.

Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>

test/functional/api/cas/casadm_parser.py

@@ -12,11 +12,10 @@ from test_utils.size import parse_unit
 from storage_devices.device import Device
 from api.cas.cache_config import *
 from api.cas.casadm_params import *
+from api.cas.version import CasVersion
 from datetime import timedelta
 from typing import List
 
-from packaging import version
-
 from api.cas import casadm
 from api.cas.cache_config import *
 from api.cas.casadm_params import *
@@ -275,4 +274,4 @@ def get_seq_cut_off_parameters(cache_id: int, core_id: int):
 def get_casadm_version():
     casadm_output = casadm.print_version(OutputFormat.csv).stdout.split('\n')
     version_str = casadm_output[1].split(',')[-1]
-    return version.parse(version_str)
+    return CasVersion.from_version_string(version_str)