Helpful message for create command when param is missing

[vladimirvivien]

When creating a volume, if a param is missing, polly simply errors out. Instead it should provide helpful message indicating the source of error.

The following shows what happen when I tried to create a volume with Polly cli tool.

polly volume create --name=testvol --servicename=swarm_virtualbox -l debug
DEBU[0000] updated log level                             logLevel=debug
FATA[0000] http error                                    status=500

The problem was that the size param is missing.

[clintkitson]

@dvonthenen Would be great to loop this fix in for 0.1.1.

[davidvonthenen]

This issue should be fixed now. If you are still seeing this, please reopen or file a new bug.