Update Cabal configuration

[jpvillaisaza]

Change the Cabal configuration and rename the package to datetime. This repository will replace the one listed in http://hackage.haskell.org/package/datetime-0.2.1, which no longer exists, as suggested by @jdevelop, one of the current maintainers of datetime.

See #3.

[jpvillaisaza]

@jsl I'm going to add your email as maintainer in the Cabal file. After upgrading datetime in Hackage, we can submit it to Stackage as well.

[jpvillaisaza]

@jsl Oh, I take that back, the maintainer email is a Stack Builders email, I'll leave that one.

[jpvillaisaza]

I'm going to bump the version to 0.2.5 and add a deprecated note asking to use datetime (as of version 0.3.0) instead.

[jpvillaisaza]

@jsl I take the uploading part back. Can you add me as maintainer (jpvillaisaza) to datetime-sb or upload version 0.2.5 after merging to master? I'll push the changes in a second.

[jpvillaisaza]

@jsl If you're going to upload, I added a tag for version 0.2.5 https://github.com/stackbuilders/datetime/tree/v0.2.5. If not, I have the .tar.gz ready. Thanks.