This patch fixes some wrong artifact names for fabric-ca in
`fabric-samples/test-network/network.sh`.
Artifacts names which include `issuerPublicKey` and `issuerRevocationPublicKey`
should start with capital letters.
Due to the wrong names, some files remain even after running the command to
bring down networks using fabric-ca.
Signed-off-by: Tatsuya Sato <Tatsuya.Sato@hal.hitachi.com>