README.md: Update kernel to v4.9.27

Author: rajivr

README.md

@@ -23,7 +23,7 @@ system that powers [AWS](https://aws.amazon.com/).
 <a name="container_host"></a>
 ### Container Host
 
-* LTS Kernel [v4.9.20](https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.20)
+* LTS Kernel [v4.9.27](https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.27)
 * VirtualBox Guest Additions [v5.1.20](http://download.virtualbox.org/virtualbox/5.1.20/)
 * Docker [v1.12.6](https://github.com/docker/docker/releases/tag/v1.12.6)
 * Device mapper storage driver in [direct-lvm](https://docs.docker.com/v1.12/engine/userguide/storagedriver/device-mapper-driver/#/configure-direct-lvm-mode-for-production) mode