Ironic: Remove few misguided negative tests on ports

As part of https://bugs.launchpad.net/ironic/+bug/1398350 Ironic is fixing
a bug where the josn-fields in the resources only accepted string and
int, as part of the work Ironic will now support any json serializable
value on those fields.

Some negative tests on ports were considering float to be a malformed
value, which they are not. This patch is removing those tests.

This patch is also adding tests checking for the new supported values
in the API.

The patch in Ironic adding support for multiple types is this one:
https://review.openstack.org/#/c/137762/

Change-Id: I02e95d77a90b3c1a8e203cf83cc0ec28b5460e58
Merge "Ironic: Remove few misguided negative tests on ports"