Fix warning "Adapter did not report total number of specs"

[JamieMason]

When running karma-benchmark, the following appears in the output.

17 03 2017 12:00:10.717:WARN [PhantomJS 2.1.1 (Mac OS X 0.0.0)]: Adapter did not report total number of specs.

An example of how to do this can be seen in karma-qunit.

[JamieMason]

A fix is available in develop but will be released at a later date.