Update apply.rb

File.exist? throws an exception if file_name is nil instead of "". 

Use .to_s to normalise file_name to a string rather than have an explicit nil check.
Fixing case of a nil recipe file with chef apply

Raising the error 'No recipe file was provided' with a fatal!
call when the recipe_name is nil. This case occurs when
chef-apply is called without a recipe name argument.

Also renamed the apply spec file to apply_spec so it is picked
up by an rspec test run. Fixed a typo in the file where it was
creating a 'Chef::Application::Recipe' for @app instead of
'Chef::Application::Apply'
Fixing travis-ci failure.

Travis-CI runs failed due to Chef::Application::Apply picking
up the explicit --format parameter and attempting to use it.

Using ARGV.clear before a call to @app.reconfigure fixes this
failure for now.

Also a whitespace modification in apply.rb
Expanding the file name before checking existance
Making sure the right data is used throughout the test
Ensuring no arguments interfere with tests

Pushed the ARGV.clear statement required for the apply_spec
file up into a before(:suite).
Merge branch 'patch-1' of github.com:workmad3/chef into sersut/rebase-chef-1971
Merge pull request #2207 from opscode/sersut/rebase-chef-1971

Rebase CHEF-1971: Report a more appropriate error when no recipe is given