consider resources for initContainers if provided in function deploym…

[abinet]

Issue Ref: #960

Description:

This PR allows to provide default resources for initContainers if they need to be created.

[abinet]

I think there is a general problem with CI build right now.
go tools vet is deprecated and should be replaced by go vet. But go vet does not work properly with individual files (see https://circleci.com/gh/kubeless/kubeless/2633?utm_campaign=vcs-integration-link&utm_medium=referral&utm_source=github-build-link)

From other POV vetting is already included into go test by default:

As part of building a test binary, go test runs go vet on the package
and its test source files to identify significant problems. If go vet
finds any problems, go test reports those and does not run the test
binary. Only a high-confidence subset of the default go vet checks are
used. That subset is: 'atomic', 'bool', 'buildtags', 'nilfunc', and
'printf'. You can see the documentation for these and other vet tests
via "go doc cmd/vet". To disable the running of go vet, use the
-vet=off flag.

So that's why I'm going to remove ./script/validate-vet from the validation step.

[andresmgot]

Thank you for the PR! It's looking good so far :)

Regarding the issue with vet, I agree, I had to disable it for other projects as well so I am okay removing it.

I have a minor comment but apart from that, do you mind adding an example in the docs of how to use this? Maybe this section is the most appropriate for that: https://github.com/kubeless/kubeless/blob/master/docs/advanced-function-deployment.md#custom-deployment

[andresmgot]

Thank you for the changes!