Update README sync script & Contributing instructions

- Sets a default value in README sync script
  + Default to "README.md"
  + Update `.travis.yml` to reflect this change
- Update instructions for syncing README when adding a command
  + Previously set to copy the output from an `aptible help` call
  + Instead, leverage the README usage sync script
- Updates Contributors in README

.travis.yml

@@ -8,5 +8,5 @@ rvm:
 
 script:
   - bundle exec rake
-  - bundle exec script/sync-readme-usage README.md
+  - bundle exec script/sync-readme-usage
   - git diff --exit-code

README.md

@@ -70,7 +70,7 @@ Commands:
 1. Fork the project.
 1. Commit your changes, with specs.
 1. Ensure that your code passes specs (`rake spec`) and meets Aptible's Ruby style guide (`rake rubocop`).
-1. If you add a command, update this README with the output of `aptible help | grep -v help`.
+1. If you add a command, sync this README (`bundle exec script/sync-readme-usage`).
 1. Create a new pull request on GitHub.
 
 ## Contributors
@@ -82,6 +82,7 @@ Commands:
 * Daniel Levenson ([@dleve123](https://github.com/dleve123))
 * Ryan Aipperspach ([@ryanaip](https://github.com/ryanaip))
 * Chas Ballew ([@chasballew](https://github.com/chasballew))
+* Chet Bortz ([@cbortz](https://github.com/cbortz))
 
 ## Copyright and License
 

script/sync-readme-usage

@@ -1,7 +1,7 @@
 #!/usr/bin/env ruby
 require 'open3'
 
-USAGE = ARGV.fetch(0)
+USAGE = ARGV.fetch(0, 'README.md')
 
 puts "Sync CLI usage in #{USAGE}"