Add test case for virConnect

Add a connect_attributes.py for testing API: isAlive, getType, getURI,
getHostname, getSysinfo, getCapabilities.

Signed-off-by: Jincheng Miao <jmiao@redhat.com>
Add connection_nodeinfo test case

The connection_nodeinfo.py test the node infomation the virConnect saved,
like: arch, memory, cpus.

Signed-off-by: Jincheng Miao <jmiao@redhat.com>
Add connection_version test case

The connection_version.py test the version of libvirt and hypervisor
the virConnect saved.
Currently, hypervisor checking only support qemu and lxc, need expanding
more hypervisors in furture.

Signed-off-by: Jincheng Miao <jmiao@redhat.com>
Add test_connection.conf

Signed-off-by: Jincheng Miao <jmiao@redhat.com>