installation: bump `yadageschemas` to 0.7.4
installation: bump `yadageschemas` to 0.7.4

* Because of reanahub/reana-workflow-engine-yadage#36
  we use `yadageschemas=0.7.4`

Signed-off-by: Diego Rodriguez <288245649d05cf8f96289b2b35cece8d6bcb04be@cern.ch>

reanahub/reana-client,reanahub/reana-client