defensive check for 0 shas in resource_match

[#72898348]

Signed-off-by: Michael Fraenkel <fraenkel@us.ibm.com>
Sort the buildpacks by priority via the Controller

[#70609794]

Signed-off-by: Julian Friedman <julz.friedman@uk.ibm.com>
Bump vendor/errors to latest

[#72898348]

Signed-off-by: Julian Friedman <julz.friedman@uk.ibm.com>