nomad: update to 0.8.7.

Also removes unneeded do_build and vbin from template.

srcpkgs/nomad/template

@@ -1,6 +1,6 @@
 # Template file for 'nomad'
 pkgname=nomad
-version=0.8.6
+version=0.8.7
 revision=1
 build_style=go
 go_import_path="github.com/hashicorp/nomad"
@@ -10,7 +10,7 @@ maintainer="iaroki <iaroki@protonmail.com>"
 license="MPL-2.0"
 homepage="https://www.nomadproject.io/"
 distfiles="https://${go_import_path}/archive/v${version}.tar.gz"
-checksum=e69b447dcc2caeb3d5ecf904cf3c8f327a5185a84442ee4241a796d89f96e143
+checksum=f74eac627de69190e586358b1956573a0ae1a40d0755ecdee163016949f9c7fe
 patch_args="-Np1"
 
 pre_build() {
@@ -22,13 +22,7 @@ pre_build() {
 	cd -
 }
 
-do_build() {
-	: ${go_package:=$go_import_path}
-	go build -o bin/nomad -x -tags "${go_build_tags}" -ldflags "${go_ldflags}" ${go_package}
-}
-
-do_install() {
-	vbin bin/nomad
+post_install() {
 	vlicense LICENSE
 	vsconf dist/server.hcl
 	vsconf dist/client.hcl