fix: sequel migration 25 for mysql

Author: bethesque

db/migrations/25_make_pv_pacticipants_mandatory.rb

@@ -1,8 +1,16 @@
 Sequel.migration do
   up do
+    PactBroker::MigrationHelper.with_mysql do
+      run("SET FOREIGN_KEY_CHECKS = 0")
+    end
+
     alter_table(:pact_versions) do
       set_column_not_null(:consumer_id)
       set_column_not_null(:provider_id)
     end
+
+    PactBroker::MigrationHelper.with_mysql do
+      run("SET FOREIGN_KEY_CHECKS = 1")
+    end
   end
 end