fix for TypeInitialization exception

Error during fail reporting: System.TypeInitializationException: The type initializer for 'Gdip' threw an exception. ---> System.DllNotFoundException: Unable to load shared library 'libdl' or one of its dependencies. In order to help diagnose loading problems, consider setting the LD_DEBUG environment

problem as described here https://github.com/dotnet/corefx/issues/25102

Dockerfile

@@ -1,5 +1,7 @@
 FROM microsoft/dotnet:2.2-sdk AS build-env
 
+RUN apt-get update && apt-get install -y libc6-dev libgdiplus
+
 COPY / ./tests
 
 RUN sed -i 's/let browserUrl = /let browserUrl = "http:\/\/testbrowser:4444\/wd\/hub\/" \/\/ /g' tests/Program.fs