Create core directory to contain most of code not in object classes used by tests

Change-Id: I9aec6c55ccd71894182057d36e0025b69925d314
diff --git a/src/osmo_ms_driver/__main__.py b/src/osmo_ms_driver/__main__.py
index a752c37..a4276d9 100644
--- a/src/osmo_ms_driver/__main__.py
+++ b/src/osmo_ms_driver/__main__.py
@@ -22,7 +22,7 @@
 from .cdf import cdfs
 from .starter import BinaryOptions, MobileTestStarter
 from .test_support import imsi_ki_gen
-from osmo_gsm_tester import log, util
+from osmo_gsm_tester.core import log, util
 from osmo_gsm_tester import ms_osmo_mobile
 
 # System modules
diff --git a/src/osmo_ms_driver/event_server.py b/src/osmo_ms_driver/event_server.py
index ce9d5c1..fb8a6c7 100644
--- a/src/osmo_ms_driver/event_server.py
+++ b/src/osmo_ms_driver/event_server.py
@@ -1,5 +1,5 @@
 
-from osmo_gsm_tester import log
+from osmo_gsm_tester.core import log
 
 import time
 
diff --git a/src/osmo_ms_driver/simple_loop.py b/src/osmo_ms_driver/simple_loop.py
index 29a4b5b..373fa20 100644
--- a/src/osmo_ms_driver/simple_loop.py
+++ b/src/osmo_ms_driver/simple_loop.py
@@ -15,7 +15,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from osmo_gsm_tester import log
+from osmo_gsm_tester.core import log
 
 import os
 import selectors
diff --git a/src/osmo_ms_driver/starter.py b/src/osmo_ms_driver/starter.py
index 8757e40..702baf0 100644
--- a/src/osmo_ms_driver/starter.py
+++ b/src/osmo_ms_driver/starter.py
@@ -16,7 +16,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from osmo_gsm_tester import log, util, process, template
+from osmo_gsm_tester.core import log, util, process, template
 
 from .test_support import ResultStore
 
diff --git a/src/osmo_ms_driver/test_support.py b/src/osmo_ms_driver/test_support.py
index ce3f5f1..cb2b9af 100644
--- a/src/osmo_ms_driver/test_support.py
+++ b/src/osmo_ms_driver/test_support.py
@@ -16,7 +16,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from abc import ABCMeta
-from osmo_gsm_tester import log
+from osmo_gsm_tester.core import log
 
 import time