Health check on beaglebone black does not always work reliably

Issue Background

Sometimes the health check fails due to a time out; run it again and it is ok

Issue description

It's unclear what is provoking this problem maybe the timeout value needs tweaking? We'll investigate further if this is a common problem, it maybe less of a problem if the kernel is always being used from the local webserver (in testing we've been using the linaro one for faster checking)

Acceptance criteria

When we don't see sporadic failures from a BBB health check