When doing:
```
cabal upload dist-newstyle/sdist/postgrest-7.0.1.tar.gz
```
The following error is shown:
```
Error: Invalid package
'ghc-options: -Wall -Werror' makes the package very easy to break with
future GHC versions because new GHC versions often add new warnings.
Use just 'ghc-options: -Wall' instead. Alternatively, if you want to
use this, make it conditional based on a Cabal configuration flag
(with 'manual: True' and 'default: False') and enable that flag
during development.
```
Put -Werror in a cabal flag to work around this restriction.
* Static docker image
* added tags for latest and with version
* add postgrest repository to docker image name
* set creation date on nix docker images
