fatal: bad revision 'HEAD' on first add

[Cal Bryant]

Original report: #8 (comment) courtesy of @ghistes

Cause:

dstask/git.go

Line 37 in e4d8034

 if RunGitCmd(repoPath, "diff-index", "--quiet", "HEAD", "--") == nil { 

Solution is probably to see if anything is in .git/objects

[Cal Bryant]

Fixed in master.