Use old style hash for older Ruby

Author: wbreeze

lib/rspec/rails/matchers/have_http_status.rb

@@ -292,15 +292,15 @@ def failure_message_when_negated
           if 5 < ::Rails::VERSION::MAJOR ||
              (::Rails::VERSION::MAJOR == 5 && 2 <= ::Rails::VERSION::MINOR)
             RESPONSE_METHODS = {
-              success: 'successful',
-              error: 'server_error',
-              missing: 'not_found'
+              :success => 'successful',
+              :error => 'server_error',
+              :missing => 'not_found'
             }.freeze
           else
             RESPONSE_METHODS = {
-              successful: 'success',
-              server_error: 'error',
-              not_found: 'missing'
+              :successful => 'success',
+              :server_error => 'error',
+              :not_found => 'missing'
             }.freeze
           end