Fix for RPM error "Unable to open temp file" #228

defaine _tmppath when calling rpmbuild
Fix for RPM error "Unable to open temp file" #228

define _tmppath when calling rpmbuild using temporary directory
Fix for RPM error "Unable to open temp file" #228

define _tmppath when calling rpmbuild using temporary directory and
cleanup temporary directory afterwards.
Merge pull request #229 from grahamar/master

Fix for RPM error "Unable to open temp file" #228