gherkin-lint

• Adding linting (eslint)
• Adding instructions about installing and running the demo on the readme
• Fixing rule for empty feature files

Removing fs-extra as a dependency and using fs instead

• Renaming the 'exclude' option to 'ignore'
• Adding the ability to ignore files by adding a gherkin-lintignore file to your working directory
• Updating documentation

Fixing rule no-files-without-scenarios

Changing the --exclude option to take in glob patterns instead of regular expressions

• Improving stylish format (making all columns align, adding spacing between errors of separate files, changing color for line no. and rule name from yellow to gray)
• Fixing a bug where the no-dupe-scenario-names rule would print the name of the current scenario in the list of dupes
• Fixing a bug where the no-dupe-feature-names rule would print the name of the current file in the list of dupes
• Adding test files for all the rules
• Adding a "test" command that runs the linter against the test files with all the rules turned on