install abends if config yaml uses 2 spaces for indentation#364

I've just found out that I get the following errors, if the `install.conf.yaml` uses 2 spaces for indentation rather than 4. ``` All targets have been cleaned An error was encountered while executing action link 'NoneType' object has no attribute 'get' Action link not handled An error was encountered while executing action create 'NoneType' object has no attribute 'get' Action create not handled An error was encountered while executing action link 'NoneType' object has no attribute 'get' Action link not handled ``` I thought the config yaml file has to be a valid yaml file, but apparently this is not the case. It specifically requires an indentation with 4 spaces. @anishathalye can you please shed some light on this? According to every yaml validator my config file is valid, but `install` abends with the above messages. All is well again, when I change to 4 spaces.