fix(commitpkg): ensure the PKGBUILD is version controlled

Early exit in case the PKGBUILD is not yet properly under version
control, which can happen for freshly initialized repositories.
Furthermore print an appropriate error message including a hint how to
resolve this.

Fixes #154
Fixes #167

Signed-off-by: Christian Heusel <christian@heusel.eu>
Signed-off-by: Levente Polyak <anthraxx@archlinux.org>

src/commitpkg.in

@@ -111,7 +111,7 @@ if (( ${#validpgpkeys[@]} != 0 )); then
 fi
 
 # find files which should be under source control
-needsversioning=()
+needsversioning=(PKGBUILD)
 for s in "${source[@]}"; do
 	[[ $s != *://* ]] && needsversioning+=("$s")
 done