Fix Typo in README

[schbetsy]

Fix copy-paste error: This repo doesn't use swagger

Checklist

• Changes are limited to a single goal (no scope creep)
• Code can be automatically merged (no conflicts)
• Code follows the standards laid out in the front end playbook
• Passes all existing automated tests
• New functions include new tests
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged
• Visually tested in supported browsers and devices
• Project documentation has been updated (including the "Unreleased" section of the CHANGELOG)

[coveralls]

Coverage remained the same at 100.0% when pulling 0a542a9 on readme-typo into 06b2cc8 on master.