Upgrade dev dependencies and fix tests to support pytest-asyncio strict mode

tests/compute/vmware/test_vmware_manager.py

@@ -16,13 +16,12 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
-import pytest
+import pytest_asyncio
 
 from gns3server.compute.vmware import VMware
 
 
-@pytest.fixture
-@pytest.mark.asyncio
+@pytest_asyncio.fixture
 async def manager(port_manager):
 
     m = VMware.instance()