Open up the App.config file in your Test project and add
<unitTestProvider name="MsTest" />
to the specFlow Element. The resulting XML should look like this...
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<section name="specFlow" type="TechTalk.SpecFlow.Configuration.ConfigurationSectionHandler, TechTalk.SpecFlow"/>
</configSections>
<specFlow>
<unitTestProvider name="MsTest" />
</specFlow>
</configuration>
Next step is to regenerate your specflow features to use the new MSTest stuff... and Job Done!