Fix collector provider installation detection for 19.216-33 on Systemd platforms

Added cutoffTimestamp and cutoffRelativeTime as optional properties.

This would fix #155.

As of 19.216-33, the collector uses Systemd on platforms that support it and no
longer drops off an `/etc/init.d/collector` file.

This should mean that the Systemd hack at
https://github.com/SumoLogic/sumologic-collector-chef-cookbook/blob/v1.2.23/providers/default.rb#L169
can be deleted whenever it's safe to re-break compatibility with earlier
versions of the collector.

These are automatically generated as of ChefSpec 7.1.0.

Offenses:

libraries/provider_source.rb:34:21: C: Reverse the order of the operands /password/i === config_json.
          sensitive(/password/i === config_json) # rubocop:disable Style/CaseEquality
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^

Signed-off-by: JJ Asghar <jj@chef.io>

* #73: Use node run state for credentials

* #73: Add README and CHANGELOG, make foodcritic happy

* #73: Make it clear in the README.md regarding the security concerns as to managing sumo credentials

* #73: Add deprecation warning regarding "Persisting sensitive information in node attributes"

Most of these were added relatively recently, with v19.182.

Prep for v1.2.23 release

relates to #141

We now allow using `node['sumologic']['init_style']` with any valid chef provider. Default is `nil` and will defer to ohai unless overridden.

Note: it does not attempt an validation that you chose a valid provider.

Signed-off-by: Ben Abrams <me@benabrams.it>

Prep for v1.2.22 release

CHANGELOG and misc repo changes:

- clairfy versioning of project to (now) use semver2
- Switch CHANGELOG format to follow good practices from http://keepachangelog.com
- lock chef gems to chef 12 in preperation for dropping chef 11 support.

This should help with two issues regarding collector registration:

* The collector init script starts the service asynchronously, so Chef
  considers the service started, even if the registration fails and it bails
  out seconds later.
* When the collector registers itself with Sumo Logic, it overwrites the
  user.properties file. This causes the second Chef run to regenerate the
  template once more and signal another collector restart.

Chef 13 was released today and seems to no longer be able to handle resource
classes from LWRP providers in the same way.

```
   ================================================================================
   Error executing action `install` on resource 'sumologic_collector[Install Sumo Logic collector]'
   ================================================================================

   NameError
   ---------
   uninitialized constant Chef::Resource::SumologicCollector

   Cookbook Trace:
   ---------------
   /tmp/kitchen/cache/cookbooks/sumologic-collector/providers/default.rb:10:in `load_current_resource'
```

This change is now documented under "DSL-based custom resources and providers
no longer get module constants" [here](https://docs.chef.io/release_notes.html).

There's another [PR](https://github.com/SumoLogic/sumologic-collector-chef-cookbook/pull/121)
open to change this `converege_if_changed` block back to a `converge_by`. However, the block
shouldn't be needed at all, and removing it will also keep [#112](https://github.com/SumoLogic/sumologic-collector-chef-cookbook/issues/112)
solved.

The default values for this are set in wrapper.conf but can be overridden in
user.properties.

There seems to be a race condition in the collector where, if it's restarted
while in the middle of registering, it can end up registering twice. Delaying
the restart until the end of the Chef run should help with that, as well as
limiting the total number of restarts if resources in a wrapper cookbook
are sending restart notifications for other things as well.

Otherwise, Chef manages the service by calling the init script directly. This
leaves Systemd out of sync and `service collector *` claiming the service has
crashed while `/etc/init.d/collector *` properly reports that it's running.

Also enables support in the service for the status and restart commands.

This template, as used in the [sumologic_collector provider](https://github.com/SumoLogic/sumologic-collector-chef-cookbook/blob/master/providers/default.rb#L47),
triggers a restart notification. The presence of a timestamp means the file
content changes and a new restart notification is sent for every Chef run.

    - Pin to the latest non 3.x release https://github.com/chef/chef-vault/blob/master/Changelog.md

[CI] improve lint process:

- switch from using chefdk binaries to bundled gem commands
- use ruby 2.3
- bumped (and locked) dependencies that made sense
- appease foodcritic