bug fix: failed to update vm with unicode name

update a vm's name with unicode name, kimchi will report error.
$ curl -u <user> -H 'Accept: application/json' \
-H 'Content-type: application/json' \
http://localhost:8000/vms/u13.10 -X PUT -d '
{"name":  "kīмсhī-∨м"}'

There are two bugs:
1. typo
encode the ident with "utf8" when HTTPRedirect
change it to "utf-8"

2. The name form libvirt is str, need decode.
ref:
https://github.com/kimchi-project/kimchi/wiki/support-unicode

Signed-off-by: ShaoHe Feng <shaohef@linux.vnet.ibm.com>
update test case for updating vm with unicode name

update test case for it to avoid regression.

Signed-off-by: ShaoHe Feng <shaohef@linux.vnet.ibm.com>
change the vm name in test case

change kīмkhī to kīмсhī
kīмсhī looks like the acssii "kimchi"

Signed-off-by: ShaoHe Feng <shaohef@linux.vnet.ibm.com>