Fixed Rubocop offenses

Author: lasseebert

lib/grape/validations/validators/multiple_params_base.rb

@@ -15,7 +15,7 @@ def scope_requires_params
       end
 
       def keys_in_common(resource_params)
-        return [] unless Hash === resource_params
+        return [] unless resource_params.is_a?(Hash)
         (all_keys & resource_params.stringify_keys.keys).map(&:to_s)
       end
 

spec/grape/validations_spec.rb

@@ -1146,7 +1146,7 @@ module SharedParams
             'mutually_exclusive works!'
           end
 
-          post '/mutually_exclusive', wine: "2015 sauvignon"
+          post '/mutually_exclusive', wine: '2015 sauvignon'
           expect(last_response.status).to eq(400)
           expect(last_response.body).to eq 'wine is invalid'
         end