Add support for Masakari / Instance-HA

Add support for Masakari / Instance-HA

Signed-off-by: Maximilian Sesterhenn <maximilian.sesterhenn@wiit.cloud>

Merge pull request openstack-exporter#447 from fnzv/fix_large_availab…

…le_ipv6

Fixing cannot unmarshal into big.int large network_ip_availabilities_total metric

Resolve openstack-exporter#289 | Add `floating_ips` label to port

* Added the 'floating_ips' label to the neutron-port metric
* If a port has more than one fixed_ip,
  they are now joined into a comma-separated string

Update readme references

Signed-off-by: Jorge Niedbalski <j@calyptia.com>

release v1.5.0

Signed-off-by: Jorge Niedbalski <jnr@metaklass.org>

Released version 1.4.0

Signed-off-by: Jorge Niedbalski <jnr@metaklass.org>

Release v1.3.0

Signed-off-by: Jorge Niedbalski <jorge.niedbalski@canonical.com>

Release v1.2.0

Signed-off-by: Jorge Niedbalski <jnr@metaklass.org>

Release of v1.1.0

Signed-off-by: Jorge Niedbalski <jnr@metaklass.org>