Add a .gitignore file for the vendor/ directory
Minor CS changes
Add checking of nbf claim
Add specific exceptions for checking claims. Fix bad tests for exp and nbf. RE: firebase/php-jwt#20
Some minor cleanup from @brendo's PR with a quick rename
Merge branch 'brendo-integration' into integration
Porting @brylie's change with a small modification
Merge pull request #23 from firebase/integration

This closes #22 and #21