PetHub logo update

Copy these files into your existing PetHub installation:
  includes/header.php
  includes/footer.php
  assets/css/brand.css
  assets/images/pethub-logo.png

The supplied original PNG is used in the header, footer, browser tab and Apple
touch icon. Its transparent background and original proportions are preserved.
The logo fits desktop, tablet and mobile layouts, including sign-in/register.

Keep your existing config/config.php and uploads folder. No database import or
setup is required. Hard-refresh your browser if the old tab icon is cached.
