test.sh: Force py == 1.5.4 on Centos 6
test.sh: Force py == 1.5.4 on Centos 6

Version 1.6.0 of the py module is incompatible with Python-2.6.

DBuildService/osbs-client,projectatomic/osbs-client,DBuildService/osbs-client,projectatomic/osbs-client