Unified dependency requirement into single file

Use the requirements.txt as the single file to include all the
dependencies. This is to unblock the jenkins verify job failure.

Change-Id: If68b61826bfe8d32d08e59d9b67a8791cc878833
Signed-off-by: Lianhao Lu <lianhao.lu@intel.com>
Issue-Id: VNFSDK-69
4 files changed