Bump fog-openstack, rspec-rails and fog-core (#8877)

Bump fog-openstack, rspec-rails and fog-core (#8877)

Bumps [fog-openstack](https://github.com/fog/fog-openstack), [rspec-rails](https://github.com/rspec/rspec-rails) and [fog-core](https://github.com/fog/fog-core). These dependencies needed to be updated together.

Updates `fog-openstack` from 0.3.6 to 1.0.3
- [Release notes](https://github.com/fog/fog-openstack/releases)
- [Changelog](https://github.com/fog/fog-openstack/blob/master/CHANGELOG.md)
- [Commits](https://github.com/fog/fog-openstack/compare/v0.3.6...v1.0.3)

Updates `rspec-rails` from 3.7.2 to 3.8.0
- [Release notes](https://github.com/rspec/rspec-rails/releases)
- [Changelog](https://github.com/rspec/rspec-rails/blob/master/Changelog.md)
- [Commits](https://github.com/rspec/rspec-rails/compare/v3.7.2...v3.8.0)

Updates `fog-core` from 1.45.0 to 2.1.2
- [Release notes](https://github.com/fog/fog-core/releases)
- [Changelog](https://github.com/fog/fog-core/blob/master/changelog.md)
- [Commits](https://github.com/fog/fog-core/compare/v1.45.0...v2.1.2)

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