Time-out using cluster context at 5s

This makes kubetrim try for 5s before giving up on a context/
cluster.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Implement keep file for #6

Closes #6 by implementing a keep/exclusions file.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

add compression to binaries

Signed-off-by: Richard Gee <[email protected]>

Don't remove if there are zero or no reachable contexts

When run on start-up, if there is no WiFi available, we want to
preserve the clusters, or allow the user to --force the removal.

When there are zero changes to make, don't write out the file.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Add .DEREK.yml file for release notes

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Add README

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>