adding new version of cx_Oracle

Updated cx_Oracle from 5.1 to 5.1.3 version.

It was tested only in SLC6 and pushed to comp_gcc481 branch.
It was tested also with SQLAlchemy 0.9.6 version [ https://github.com/cms-sw/cmsdist/pull/1029 ]. Not with 0.5.2 version.

@amaltaro @juztas @hufnagel