Update 'Common troubleshooting' text of readme.
Update 'Common troubleshooting' text of readme.

Update the 'Common troubleshooting' text of the readme file to include a possible solution to error
"Starting Spork for RSpec ERROR: Could not start Spork for RSpec/Cucumber". The solution,
recommended in issue #48, is to remove an unused /test directory from the application.

guard/guard-spork