Bump symfony/flex from 1.0.66 to 1.0.67
Bump symfony/flex from 1.0.66 to 1.0.67

Bumps [symfony/flex](https://github.com/symfony/flex) from 1.0.66 to 1.0.67.
- [Commits](https://github.com/symfony/flex/compare/v1.0.66...v1.0.67)
deathart/Forum,deathart/Forum,deathart/Forum