correct the version, in order to update by cask

[gaoyifan]

Due to the version of textmate is "latest", it cannot be update by cask. So I add the correct version information and checksum.
After update textmate.rb, the TextMate which had installed earlier cannot be uninstalled or upgraded by cask. I don't know how to solve the problem.

[vitorgalvao]

As a rule, we prefer casks that use the latest scheme. If I remember correctly (haven’t used it in a while), Textmate can auto-update, so doing it via homebrew-cask is not really an issue. See #309 for a discussion on an upgrade command. To solve your current problem, you can run brew cleanup --force -s && rm -rf "$(brew --cache)" to delete the old version (a specific cleanup for homebrew-cask is being implemented).

Regarding the merits of using latest or a specific version, please refer to #1021, and if you have anything to add, please do. In the meantime, however, since we currently still prefer to use the latest version when available, I’ll close this.