docs(tiller): Adds documentation for secret backend

fix circle not building tags

CircleCI recently skipped building tags by default, so we need to
explicitly enable it.

See https://circleci.com/docs/2.0/configuration-reference/#tags

Adding documentation on $ variable scope

as requested

Small change in README.md

There should be a colon because it precedes an explanation or an enumeration, or list.

Working on Fedora release 25 -  kubeadm v1.7.0 - kubelet v1.8.1

Tested:
- Installing/deleting Chart
- Chart upgrade and Chart rollback

Fix a small typo in `yaml_techniques.md`

Fix a typo: `coffess`.

fix(semver): fixed edge cases that do not match prerelease

Adds documentation for running `tiller` with the new secrets backend
added in #2721

pin golang.org/x/sys to master

fixes issues seen in master with `make build-cross` for windows

Document how to add an image pull secret in Helm

Provide an example of how to take an image registry, user name, and password and prepare a Secret that can be used by a pod to pull a protected container image.

chore(sprig): bump sprig to 2.14.0

ref(*): kubernetes v1.8 support

fix(tiller): Adds CRD ordering

feat(2196): secrets management 

feat(helm):Allow remote values.yaml with -f

feat(helm): Add --node-selectors, --override and --output flags to helm init

This feature enables users to specify more control over where Tiller pod
lands by allowing "node-selectors" to be specified. Alternatively, the
"--output" flag will skip install and dump Tiller's raw Deployment manifest to stdout so user may alter it as they see fit (probably with a JSON manipulation tool like jq).

Closes #2299

This adds CRD ordering into the explicit kind sorter list

Closes #2925

fix(helm): invoking getterConstructor returns downstream error now

>0.0.0-a does not match pre-releases on 0.0.0 that start with a
capital letter or number. This has to do with the ordering of
code points. Numbers and capital letters come before lowercase
letters.

>0.0.0-0 should match all valid pre-releases on 0.0.0. According
to the spec, "Numeric identifiers MUST NOT include leading zeroes."
A 0 is also the lowest code point for all the allowed characters
in a pre-release

* helm create all defined template names should be namespaced https://docs.helm.sh/chart_best_practices/#names-of-defined-templates

* Update Doc

* Update example

* Closes #2937
Added required dependency to run make test in developer's guide

* Fixed base URL appending when chart address is not absolute

* Removed requirement from developers.md

* Fixed unnecessary line breaks

* Added tests for query string repo

* Returning URL along with error

Ignore Apiversion, use Kind and Name only to search for original resource on update/delete

chore(*): bump version to v2.6.2

(cherry picked from commit a4f965e0)

Correctly persists Release upgrade failure

fix(sorter): Adds missing unit test

fix(helm):Fix dependency aliaes not working