Documentation for FlexRex integration (see #663)
Documentation for FlexRex integration (see #663)

This commit adds documentation for FlexRex integration and includes
examples of persistent volume, persitent volume claim, and pods.

oppodeldoc/rexray,thecodeteam/rexray,akutz/rexray,thecodeteam/rexray,codedellemc/rexray,oppodeldoc/rexray,akutz/rexray,emccode/rexray,codedellemc/rexray,oppodeldoc/rexray,oppodeldoc/rexray,emccode/rexray,akutz/rexray,codedellemc/rexray,cduchesne/rexray,cduchesne/rexray,emccode/rexray,thecodeteam/rexray,akutz/rexray,thecodeteam/rexray,cduchesne/rexray,akutz/rexray,oppodeldoc/rexray,cduchesne/rexray,codedellemc/rexray,codedellemc/rexray,emccode/rexray,cduchesne/rexray,akutz/rexray,codedellemc/rexray,thecodeteam/rexray,thecodeteam/rexray,cduchesne/rexray,oppodeldoc/rexray