docs(test): mention kvm as a requirement for integ tests

KVM being enabled on the host is a prerequisite
for running most of the integration tests.

Signed-off-by: Nikita Kalyazin <[email protected]>

Author: kalyazin

tests/README.md

@@ -52,7 +52,8 @@ For help on usage, see `tools/devtool help`.
 
 ### Dependencies
 
-- A bare-metal `Linux` host with `uname -r` >= 4.14.
+- A bare-metal `Linux` host with `uname -r` >= 4.14 and KVM enabled
+  (`/dev/kvm` device node exists).
 - Docker.
 
 ## Rustacean Integration Tests