Simplify the test suite decorators

This change eliminates duplicate instantiation
of pytest `skipif()` objects.

Author: kurtmckee

tests/utils.py

@@ -15,16 +15,13 @@ def key_path(key_name):
     return os.path.join(os.path.dirname(os.path.realpath(__file__)), "keys", key_name)
 
 
-def no_crypto_required(class_or_func):
-    decorator = pytest.mark.skipif(
-        has_crypto,
-        reason="Requires cryptography library not installed",
-    )
-    return decorator(class_or_func)
-
-
-def crypto_required(class_or_func):
-    decorator = pytest.mark.skipif(
-        not has_crypto, reason="Requires cryptography library installed"
-    )
-    return decorator(class_or_func)
+no_crypto_required = pytest.mark.skipif(
+    has_crypto,
+    reason="Requires cryptography library not installed",
+)
+
+
+crypto_required = pytest.mark.skipif(
+    not has_crypto,
+    reason="Requires cryptography library installed",
+)