Add dependency on Flask-Cache to support caching of query results.
Add dependency on Flask-Cache to support caching of query results.

pegasus-isi/pegasus-service,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus-service,pegasus-isi/pegasus-service,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus,pegasus-isi/pegasus