Improved tag sorting

• use sorting option of git command, it allows to sort tags by date. sort -r doesn't work properly in all cases, e.g. if there are two tags exist 0.3.9 and 0.3.68, then sort -r will return 0.3.9 as first tag

• grep "^v[0-9].[0-9].[0-9]" doesn't make sense here, git tag -l --sort=-committerdate returns only the list of tags