Update PKGBUILD to reflect restic official version numbering

doc/PKGBUILD

@@ -4,7 +4,7 @@
 # Contributor: Alexander Neumann <alexander@bumpern.de>
 options=(!strip)
 pkgname=restic-git
-pkgver=r702.c143f8c
+pkgver=v0.1.0.r172.g1f1b8e1
 pkgrel=1
 pkgdesc="restic is a program that does backups right."
 arch=('i686' 'x86_64')
@@ -21,7 +21,7 @@ importpath='github.com/restic/restic'
 
 pkgver() {
   cd "$pkgname"
-  printf "r%s.%s" "$(git rev-list --count HEAD)" "$(git rev-parse --short HEAD)";
+  git describe --long | sed 's/\([^-]*-g\)/r\1/;s/-/./g'
 }
 
 build() {