docs: add helm-edit plugin

Fix link in provenance.md

Update README to point to #charts channel on slack too

Update helm binary references to v2.5.1

Add jascott1 as maintainer and reviewer

add bacongobbler as a core maintainer

CAFile is now optional, in that case the default RootCAs are used

Handle nil responses returned from rudder funcs

ref(pkg/chartutil): replace use of 'fmt.Efforf'

Tiller panicked on nil pointer dereference when it was unable to connect
to rudder.

docs(fix): fixed misspelled word

- updated helm_test.md

fix(tiller): remove locking system from storage and rely on backend

remove tiller/environment dependency from plugin package

ref(pkg/chartutil): decrease map lookups

Include "seh" as a Helm project maintainer and reviewer

feat(2063): Better 'helm list' visibility into state of pending upgrades

Fixing typos in requirements.yaml part

Reduce comment spacing to single tab.

Make comment for PathValue more explanatory.

Fix inverted equaility check and update error message.

Move comment out of test. Move ref location in test.

Capitalize "yaml" in error message. Remove empty var from test error message.

Decrease map lookups in `chartutil.coalesceValues` and move comment to unit
test.

Closes #2663

Tiller currently hangs indefinitely when deadlocks arise from certain
concurrent operations. This commit removes the nested mutex locking
system from pkg/Storage and relies on resource contention controls in k8s.

Closes #2560

'fmt.Errorf' is unnecessary when checking for 0 length path in Values.PathValue
due to the lack of formatting. Add test covering changes.

fix(helm): fix flag parsing once and for all