Fix versions.py to include release stage

Signed-off-by: Joffrey F <[email protected]>

Merge pull request docker#2365 from docker/4.0.2-release

4.0.2 release

Merge pull request docker#2348 from docker/4.0.1-release

4.0.1 release

Merge pull request docker#2331 from docker/4.0.0-release

4.0.0 release

Add readthedocs config

Signed-off-by: Joffrey F <[email protected]>

Merge pull request docker#2299 from ulyssessouza/3.7.2-release

Bump 3.7.2 release

Merge pull request docker#2283 from ulyssessouza/3.7.1-release

3.7.1 release

Merge pull request docker#2223 from docker/3.7.0-release

3.7.0 release

Merge pull request docker#2187 from docker/3.6.0-release

3.6.0 release

Merge pull request docker#2156 from docker/3.5.1-release

3.5.1 release