improve version handling

Author: funbringer

testgres/testgres.py

@@ -1157,8 +1157,11 @@ def get_pg_config():
 pg_config_data[key.strip()] = value.strip()
 
 # Fetch version of PostgreSQL and save it as VERSION_NUM
-version_parts = pg_config_data["VERSION"].split(" ")
-version, _, _ = version_parts[-1].partition('beta')
+version = pg_config_data["VERSION"]
+version = version.split(" ")[-1] \
+.partition('devel')[0] \
+.partition('beta')[0] \
+.partition('rc')[0]
 pg_config_data["VERSION_NUM"] = version
 
 return pg_config_data