Failed nunit tests won't stop succeeding build steps

Hi.

After NUnit 3.6.0 fails some tests, additional build steps afterwards are executed, even though all steps are configured as "Execute: If all previous steps finished successfully", which is the default.

Here's an as simple as possible example of a build config that:

1. Installs nuget packages for a VS solution.
2. Using cmd.exe, prints the content of the packages folder (for diagnostic purpose).
3. Using sln build runner, compiles the code using VS2015.
4. Runs NUnit console runner, version 3.6.0.
5. Runs a Powershell script that prints "hello".

https://github.com/collector-bank/testnunit/blob/master/Teamcity_Testnunit.xml

When the tests fail, which they do 100% of the time by design, the build still prints "hello" in step #5.

It's displayed as "red" in our Teamcity (tried both 10.0.4 and 10.0.5), but in the statistics tab it considered a "success".