[pga] update go-git dependency #132
Description
The used go-git version has a bug decoding pgp signatures and hangs indefinitely. This affects indexing process.
goroutine 1943 [runnable]:
github.com/src-d/datasets/PublicGitArchive/pga-create/vendor/gopkg.in/src-d/go-git.v4/plumbing/object.(*Commit).Decode(0xc12d0944b0, 0x1477540, 0xc07ca89ec0, 0x0, 0x0)
/go/src/github.com/src-d/datasets/PublicGitArchive/pga-create/vendor/gopkg.in/src-d/go-git.v4/plumbing/object/commit.go:191 +0x3d3
github.com/src-d/datasets/PublicGitArchive/pga-create/vendor/gopkg.in/src-d/go-git.v4/plumbing/object.DecodeCommit(0x7faa2f8f2110, 0xc01a3500c0, 0x1477540, 0xc07ca89ec0, 0x0, 0x141c891, 0xda)
/go/src/github.com/src-d/datasets/PublicGitArchive/pga-create/vendor/gopkg.in/src-d/go-git.v4/plumbing/object/commit.go:66 +0x79
github.com/src-d/datasets/PublicGitArchive/pga-create/vendor/gopkg.in/src-d/go-git.v4/plumbing/object.(*storerCommitIter).Next(0xc12d006bc0, 0xc03cee6e10, 0x146ba20, 0xc12d006bc0)
/go/src/github.com/src-d/datasets/PublicGitArchive/pga-create/vendor/gopkg.in/src-d/go-git.v4/plumbing/object/commit.go:395 +0x92
github.com/src-d/datasets/PublicGitArchive/pga-create/vendor/gopkg.in/src-d/go-git.v4/plumbing/object.(*commitPreIterator).Next(0xc03cee6e70, 0x0, 0x0, 0x0)
/go/src/github.com/src-d/datasets/PublicGitArchive/pga-create/vendor/gopkg.in/src-d/go-git.v4/plumbing/object/commit_walker.go:55 +0x268
github.com/src-d/datasets/PublicGitArchive/pga-create/vendor/gopkg.in/src-d/go-git.v4/plumbing/object.(*commitPreIterator).ForEach(0xc03cee6e70, 0xc007f7a030, 0xc008927120, 0x18)
/go/src/github.com/src-d/datasets/PublicGitArchive/pga-create/vendor/gopkg.in/src-d/go-git.v4/plumbing/object/commit_walker.go:95 +0x2f