Update on black version and remove spaces

Update on the usage of the Black version, which
resolves the problem of removing leading and trailing
spaces in one-line docstrings.
psf/black#1740

docs/examples/resource_clients.py

@@ -792,7 +792,7 @@ def demo_users(client):
 
     user = client.users.create(
         metadata={},
-        spec={"username": "demo_user", "password":"demouserpassword"},
+        spec={"username": "demo_user", "password": "demouserpassword"},
     )
     print_cluster_resource(user)
 

setup.cfg

@@ -45,7 +45,7 @@ install_requires =
 
 [options.extras_require]
 dev =
-    black
+    black >= 21.4b2
     flake8
     mypy
     pytest >= 6, < 7

src/sensu_go/errors.py

@@ -2,15 +2,15 @@
 
 
 class SensuError(Exception):
-    """ Base exception for the sensu-go package. """
+    """Base exception for the sensu-go package."""
 
 
 class HTTPError(SensuError):
-    """ Error that indicates a problem with backend connection. """
+    """Error that indicates a problem with backend connection."""
 
 
 class ResponseError(SensuError):
-    """ Error that indicates a problem with backend's response. """
+    """Error that indicates a problem with backend's response."""
 
     def __init__(self, msg: str, url: str, status: int, text: str) -> None:
         self.url = url
@@ -23,4 +23,4 @@ def __init__(self, msg: str, url: str, status: int, text: str) -> None:
 
 
 class AuthError(ResponseError):
-    """ Error that indicates a problem with credentials. """
+    """Error that indicates a problem with credentials."""