Bail out when VM is not ready after some time

Previously this situation was ignored resulting
in potential failures later on
Increase wait_for_ready_vm timeout to 20 seconds
Refresh VM details while waiting for VM to become ready
Add support for automatically resizing volumes
Bump dependency requirements
Merge pull request #2 from epienbroek/ready_status_logic

Various improvements in "make sure VM is ready to start" logic
Merge pull request #3 from epienbroek/volume_extend

Add support for automatically resizing volumes
Use the oVirt REST API to find out the guest IP address

This replaces the old nmap broadcast/arp hack which was
previously used to find out the guest IP address and also
allows the vagrant-ovirt plugin to be used from different
network subnets.

Requires https://github.com/fog/fog/pull/3162 and a box
image which contains the package 'ovirt-guest-agent'
Merge pull request #1 from epienbroek/guest_ips

Use the oVirt REST API to find out the guest IP address
Version bump.
Fixing README
Prevent endless loop when SSH authentication fails
Allow network interface type to be specified

This change also fixes the following error on modern RHEV/oVirt environments:
ERROR vagrant: #<VagrantPlugins::OVirtProvider::Errors::AddInterfaceError: Error while adding new interface to VM. rhevm is not a member of NicInterface. Possible values for NicInterface are: e1000, virtio, rtl8139, rtl8139_virtio, spapr_vlan>
ERROR vagrant: Error while adding new interface to VM. rhevm is not a member of NicInterface. Possible values for NicInterface are: e1000, virtio, rtl8139, rtl8139_virtio, spapr_vlan
Merge pull request #4 from epienbroek/ssh_timeout

Prevent endless loop when SSH authentication fails
Merge pull request #5 from epienbroek/add_interface

Allow network interface type to be specified