Re-factor the ORM tests to use randomized fake data

- create `*Factory` classes with fakerboy and faker that generate
  randomized instances of the ORM models
- add new pytest marker: "db" are the integration tests involving the
  database whereas "e2e" will be all other integration tests
- streamline the docstrings in the ORM models

setup.cfg

@@ -89,6 +89,8 @@ extend-ignore =
     # Comply with black's style.
     # Source: https://github.com/psf/black/blob/master/docs/compatible_configs.md#flake8
     E203, W503, WPS348,
+    # Allow underscores in numbers.
+    WPS303,
     # f-strings are ok.
     WPS305,
     # Classes should not have to specify a base class.
@@ -139,14 +141,24 @@ per-file-ignores =
     tests/*.py:
         # Type annotations are not strictly enforced.
         ANN0, ANN2,
+        # The `Meta` class inside the factory_boy models do not need a docstring.
+        D106,
         # `assert` statements are ok in the test suite.
         S101,
+        # The `random` module is not used for cryptography.
+        S311,
         # Shadowing outer scopes occurs naturally with mocks.
         WPS442,
         # Modules may have many test cases.
         WPS202,WPS204,WPS214,
+        # Do not check for Jones complexity in the test suite.
+        WPS221,
         # No overuse of string constants (e.g., '__version__').
         WPS226,
+        # We do not care about the number of "# noqa"s in the test suite.
+        WPS402,
+        # Allow closures.
+        WPS430,
         # Numbers are normal in test cases as expected results.
         WPS432,
 
@@ -166,6 +178,7 @@ show-source = true
 # wemake-python-styleguide's settings
 # ===================================
 allowed-domain-names =
+    data,
     obj,
     param,
     result,
@@ -274,4 +287,5 @@ console_output_style = count
 env =
     TESTING=true
 markers =
-    e2e: integration tests, incl., for example, tests touching the database
+    db: tests touching the database
+    e2e: non-db integration tests