Fix typo and add dep

Author: Ge0rg3

flask_parameter_validation/parameter_validation.py

@@ -77,8 +77,8 @@ async def nested_func(**kwargs):
                     except Exception as e:
                         return self.custom_error_handler(e)
                 validated_inputs[expected.name] = new_input
-            
-            if asyncio.iscoroutinefunctions(f):
+
+            if asyncio.iscoroutinefunction(f):
                 return await f(**validated_inputs)
             else:
                 return f(**validated_inputs)

setup.py

@@ -28,6 +28,7 @@
     platforms='any',
     install_requires=[
         'Flask',
+        'flask[async]',
         'python-dateutil',
     ],
     classifiers=[