Use described_recipe variable for reduced repetition
Use described_recipe variable for reduced repetition

Instead of repeating the name of the recipe we're testing against, we
can instead use the `described_recipe` variable ChefSpec provides for
us.

As part of #82.

Signed-off-by: Jamie Tanna <b4dde37aa2aac745c0e6c43447507eaeace3e59f@jamietanna.co.uk>

opscode-cookbooks/maven,opscode-cookbooks/maven,chef-cookbooks/maven,chef-cookbooks/maven