[FEATURE] Optional IOPS option in aws volume

[citrocity]

• added option for IOPS for aws volume. Example:

  volume_size: 1, encrypted: True, delete_on_termination: true }
        - { device_name: "/dev/sdg", mountpoint: "/media/mysvc", fstype: "ext4", volume_type: "gp2", volume_size: 1, iops: 100, encrypted: True, delete_on_termination: true }

This is optional and can be left out to have default values.

• Example files updated

• added assert for aws gp volume types as max iops is 16k

• tested it on Jenkins