Added Yandex & Ahrefs bot machines
Add detection for tablet Firefox OS
Merge pull request #78 from dougwilson/feature/firefox-os-tablet

Add detection for tablet Firefox OS
Bumps version to 1.67
v1.67

    - Adds detection for tablet Firefox OS (Douglas Christopher Wilson)
Merge pull request #76 from Perlover/new/yandex_ahrefs

Added Yandex & Ahrefs bot machines
Adds tests for Ahrefs and Yandex bots.
Bumps version to 1.68.
v1.68

    - Adds Yandex & Ahrefs bots (Perlover)