Browsersync works by injecting an asynchronous script tag (<script async>...</script>) right after the <body> tag
during initial request. In order for this to work properly the <body> tag must be present. Alternatively you
can provide a custom rule for the snippet using snippetOptions
Upgrading from 1.x to 2.x ?
Providing you haven't accessed any internal properties, everything will just work as
there are no breaking changes to the public API. Internally however, we now use an
immutable data structure for storing/retrieving options. So whereas before you could access urls like this...