tests: Use newgrp to run unit tests

Rather than set filesystem permissions on the /dev/kvm device instead
use the kvm group added by installing qemu for running the unit tests.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

Jenkinsfile

@@ -11,11 +11,10 @@ stage ("Builds") {
 			sh "nohup curl https://sh.rustup.rs -sSf | sh -s -- -y"
 		}
 		stage ('Run unit tests') {
-			sh "sudo chmod a+rw /dev/kvm"
 			sh "scripts/run_unit_tests.sh"
 		}
 		stage ('Run integration tests') {
-                        sh "sudo mount -t tmpfs tmpfs /tmp"
+			sh "sudo mount -t tmpfs tmpfs /tmp"
 			sh "scripts/run_integration_tests.sh"
 		}
 	}