[COOK-2468] set precedence level when setting node attributes

This fixes the `Chef::Exceptions::ImmutableAttributeModification` which 
is thrown when run on Chef 11+
fixes for [FC002] - Avoid string interpolation where not required
fixes for [FC016] - LWRP does not declare a default action
prefer accessor methods to accessing instance variables directly

This also fixes [FC017] in addition to providing better encapsulation.
Stop Chef::Exceptions::ShellCommandFailed deprecation messages

Checking for a non-zero exit code accomplishes the same thing as
rescuing *::ShellCommandFailed.
add `test-kitchen` 1.0 support

The 1.0 branch of test-kitchen is based on Fletcher Nichol's excellent
Jamie CI codebase.
Merge pull request #31 from opscode-cookbooks/COOK-2468

COOK-2468 - Chef 11 compat fixes