[COOK-2897] - use a string comparison not a regex match
[COOK-2897] - the command fits on one line
[COOK-2920] - add chefspec

This commit adds ChefSpec support, in the "spec" directory.

The following recipes are covered:

* default
* openjdk
* set_java_home
* ibm

The following recipes are not covered 100% (as explained):

* oracle, oracle_i386 - checks that the set_env_home recipe is
  included, doesn't test the java_ark use
* windows - pending, testing windows_package is out of scope at this
  time.

The set_java_home recipe is updated to have a single line to make it
less awkward to test (whitespace matters).