Add iops field in `slcli block volume-list`

[houstar]

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Expected Behavior

Add column 'iops' as well as lunId for example.

Actual Behavior

round-trip min/avg/max/stddev = 217.199/252.056/314.203/38.708 ms
lenos-MacBook-Pro:~ leno$ slcli block volume-list
:..........:...................:............:..............:.............:............:..............:.......:.....................:
: id : username : datacenter : storage_type : capacity_gb : bytes_used : ip_addr : lunId : active_transactions :
:..........:...................:............:..............:.............:............:..............:.......:.....................:
: 9409349 : EL571877-10 : lon02 : ENDURANCE : 100 : - : 10.1.222.7xx : 170 : - :
: 9409353 : EL571877-11 : lon02 : ENDURANCE : 100 : - : 10.1.222.1xx3 : 169 : - :
: 9482407 : EL571877-12 : lon02 : ENDURANCE : 40 : - : 10.1.222.xx1 : 171 : - :
: 9482453 : EL571877-13 : lon02 : ENDURANCE : 40 : - : 10.1.222.xx : 168 : - :

Environment Information

Operating System:
softlayer-python version (slcli --version):
slcli (SoftLayer Command-line), version 5.2.6

[allmightyspiff]

This will be added in the next release