Update pytest and pytest sugar, fix test

Bumps [pytest](https://github.com/pytest-dev/pytest) from 5.3.5 to 5.4.0.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@5.3.5...5.4.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>
Update pytest and pytest-sugar, fix test for

- Teemu/pytest-sugar#188 makes pytest-sugar compatible with pytest 5.4+
- pytest 5.4.0 flipped the signs for assert statement display, so this flips the string to match.
Fix test_fastapi.sh permissions

tests/requirements.txt

@@ -7,8 +7,8 @@ isort==4.3.21
 mypy==0.770
 pycodestyle==2.5.0
 pyflakes==2.1.1
-pytest==5.3.5
+pytest==5.4.1
 pytest-cov==2.8.1
 pytest-mock==3.1.0
-pytest-sugar==0.9.2
+pytest-sugar==0.9.3
 twine==3.1.1

tests/test_validators.py

@@ -713,7 +713,7 @@ def check_a(cls, v):
 
     with pytest.raises(ValidationError) as exc_info:
         Model(a='snap')
-    injected_by_pytest = "\nassert 'snap' == 'a'\n  - snap\n  + a"
+    injected_by_pytest = "\nassert 'snap' == 'a'\n  - a\n  + snap"
     assert exc_info.value.errors() == [
         {'loc': ('a',), 'msg': f'invalid a{injected_by_pytest}', 'type': 'assertion_error'}
     ]