Add credentials checking

* gn3/auth/authentication.py: new function `credentials_in_database`
* gn3/auth/authentication/__init__.py: replace package with module
* gn3/settings.py: new `AUTH_MIGRATIONS` configuration variable
* migrations/auth/20221103_02_sGrIs-create-user-credentials-table.py: new
  migration
* tests/unit/auth/test_credentials.py: test the `credentials_in_database`
  function
* tests/unit/conftest.py: more test fixtures

1 files changed, 19 insertions, 0 deletions

diff --git a/migrations/auth/20221103_02_sGrIs-create-user-credentials-table.py b/migrations/auth/20221103_02_sGrIs-create-user-credentials-table.py
new file mode 100644
index 0000000..3f72f3e
--- /dev/null
+++ b/migrations/auth/20221103_02_sGrIs-create-user-credentials-table.py
@@ -0,0 +1,19 @@
+"""
+create user_credentials table
+"""
+
+from yoyo import step
+
+__depends__ = {'20221103_01_js9ub-initialise-the-auth-entic-oris-ation-database'}
+
+steps = [
+    step(
+        """
+        CREATE TABLE IF NOT EXISTS user_credentials(
+            user_id TEXT PRIMARY KEY,
+            password TEXT NOT NULL,
+            FOREIGN KEY(user_id) REFERENCES users(user_id)
+        ) WITHOUT ROWID
+        """,
+        "DROP TABLE IF EXISTS user_credentials")
+]