feat(storage): in-memory & configmaps driver

feat(*): implement helm upgrade + upgrade hooks

docs(developers): recommend minikube

fix(git): ignore _dist directory

This reflects our internal decision to suggest minikube rather than
commit resources to maintaining scripts/local-cluster.sh

Closes #889

Serve charts from specified local repository path

fix(helm): fix inspect command to not panic

fix(helm): fix helmignore evaluation of dirs

feat(kube): add update logic to kube client

* Thanks for the reminder adam :)

This adds a few extra settings to the default .helmignore file. In
doing this, I found a bug that some directory patterns are not
evaluated correctly. Fixed that and added tests.

Closes #989
Closes #1027

This commit adds an Update function to the client.
The Update function takes in the modified manifests and
the original manifests. It then iterates through the modified
objects, creates objects not found in kubernetes, and updates
objects that exists but have been modified. Finally, it
iterates through the original resources and checks to see if
they have been deleted in the modified configuration and then
proceeds to delete them. #690

Check for the tgz extension while collecting chart paths

Helm can now inspect a chart if the values.yaml file is not present or
is empty.