Update tests

.coveragerc

@@ -7,6 +7,7 @@ source =
     packages/sshecret-sshd/src/sshecret_sshd
 
 omit =
+    packages/sshecret-backend/src/sshecret_backend/frontend/*
     */__init__.py
     */types.py
     */testing.py
@@ -17,7 +18,7 @@ omit =
     */test_*.py
     */conftest.py
     */site-packages/*
-concurrency = multiprocessing
+concurrency = thread
 
 [report]
 show_missing = True