Use HEAD instead of @ for Git v1 (#38)

* Go mod tidy

License: MIT
Signed-off-by: Jakub Sztandera <kubuxu@protocol.ai>

* Use HEAD instead of @ for Git v1

@ was introduced in git version 2

License: MIT
Signed-off-by: Jakub Sztandera <kubuxu@protocol.ai>

go.mod

@@ -3,21 +3,10 @@ module github.com/filecoin-project/go-sectorbuilder
 go 1.12
 
 require (
-	github.com/golangci/golangci-lint v1.17.1 // indirect
-	github.com/hashicorp/golang-lru v0.5.3 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/ipfs/go-log v0.0.1
-	github.com/neelance/parallel v0.0.0-20160708114440-4de9ce63d14c // indirect
-	github.com/opentracing/basictracer-go v1.0.0 // indirect
 	github.com/pkg/errors v0.8.1
-	github.com/prometheus/client_golang v1.1.0 // indirect
-	github.com/slimsag/godocmd v0.0.0-20161025000126-a1005ad29fe3 // indirect
-	github.com/sourcegraph/ctxvfs v0.0.0-20180418081416-2b65f1b1ea81 // indirect
-	github.com/sourcegraph/go-langserver v2.0.0+incompatible // indirect
-	github.com/sourcegraph/jsonrpc2 v0.0.0-20190106185902-35a74f039c6a // indirect
 	github.com/stretchr/testify v1.3.0
-	golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4 // indirect
 	golang.org/x/net v0.0.0-20190813141303-74dc4d7220e7 // indirect
 	golang.org/x/sys v0.0.0-20190813064441-fde4db37ae7a // indirect
-	golang.org/x/text v0.3.2 // indirect
-	golang.org/x/tools v0.0.0-20190813142322-97f12d73768f // indirect
 )

install-shared.bash

@@ -5,7 +5,7 @@ download_release_tarball() {
     __submodule_path=$2
     __repo_name=$(echo $2 | cut -d '/' -f 1)
     __release_name="${__repo_name}-$(uname)"
-    __release_sha1=$(git rev-parse @:"${__submodule_path}")
+    __release_sha1=$(git rev-parse HEAD:"${__submodule_path}")
     __release_tag="${__release_sha1:0:16}"
     __release_tag_url="https://api.github.com/repos/filecoin-project/${__repo_name}/releases/tags/${__release_tag}"