Stub HTTP requests with VCR

# What's New?

 * Added API / Ruby style guide information to README.md
 * Stubbing HTTP tests in test suite with VCR so that people don't need an AWS account to run tests.

# What's Next?

 * Get @digital-dreamer 's PR (rack-attack) merged.
 * Setup staging server
 * Install HTTPS cert on production
 * Finish the photo attachment stuff on guides