Signed-off-by: Lucas Roesler <roesler.lucas@gmail.com>

**What**
- Move the new secrets sample function to ApiKeyProtected-Secrets
- Bring back the original ApiKeyProtected sample function

Signed-off-by: Lucas Roesler <roesler.lucas@gmail.com>

**What**
- Add a description for the secret key to the api swagger spec.
- Remove optional examples from the secret management guide.
- Update the ApiKeyProtected README to point at the new guide.
- Refactor the `makeSpec` function to accept the already assembled secrets
array because this should be easier to unit test.

Signed-off-by: Lucas Roesler <lucas.roesler@gmail.com>

**What**
- During function creation, accept an array of strings defining swarm secrets
that are required for the service
- Update docs
- Add new guide on using the secrets capability
- Add new sample function to highlight using environment variables
- Update `ApiKeyProtected` sample function to utilize the new secrets
capabilities

**Why**
- This allows secrets to remain encrypted at rest instead of being unencrypted
in environment variables and yaml files.

Fixes #285

Signed-off-by: Lucas Roesler <lucas.roesler@gmail.com>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Signed-off-by: Liz Rice <liz@lizrice.com>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Converts the function names in samples.yml to lowercase

Signed-off-by: Grant Sheehan <gsheehan@gmail.com>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Note, not all `alexellis/github` references should be changed, there are
a number of repos which are not part of the openfaas org, this commit
excludes those.

Signed-off-by: John McCabe <john@johnmccabe.net>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Signed-off-by: Chanyub Park <mrchypark@gmail.com>

Signed-off-by: Chanyub Park <mrchypark@gmail.com>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

Signed-off-by: rgee0 <richard@technologee.co.uk>

Signed-off-by: Alex Ellis <alexellis2@gmail.com>