Added a link to rendered docs for the API.
Merge pull request #26 from apiaryio/hj/test-error-handling

Tests for error handling and related (minor™) fixes
Merge pull request #27 from apiaryio/hj/readme-link-rendered-docs

Added a link to rendered docs for the API
Small refactoring of error handling.
Fixed requirements.
Merge pull request #28 from apiaryio/hj/more-error-handling

Error handling tests & fixes & small refactoring
Tests for parser endpoint. Removed explicit check for empty blueprints.