fix centos build issue

In vagrant, after executing precise-build, the tarball will be
available at git/calamari-clients*tar.gz

But centos build was looking for the tarball in
git/calamari-clients/calamari-clients*tar.gz.
This is now corrected.

Signed-off-by: Kanagaraj M <kmayilsa@redhat.com>
Merge pull request #53 from kmkanagaraj/fix-centos-build

fix centos build issue