SimpleSAMLphp config files not included in deploy artifact

[dooleymatt]

Problem/motivation

1. When blt simplesamlphp:init the simplesamlphp.settings.php file gets copied into the vendor/acquia/blt/settings directory.
2. When blt deploy ... is run, it checks for the existence of that settings file in vendor/acquia/blt/settings and if it exists, simplesamlphp:deploy:config is called, which copies the config files into the vendor directory

The problem is that since simplesamlphp:init isn't run when the deploy artifact dependencies are being built, the settings file doesn't get created in the deploy artifact's vendor directory, and as a result simplesamlphp:deploy:config doesn't get called.

Proposed resolution

When blt simplesamlphp:init is run it needs to modify something outside the vendor directory which can be checked during blt deploy:build. However the only modifications that are made outside the vendor directory are modifications that have a high likelihood of being changes that would be made by a simplesaml installation that wasn't initiated by BLT.

So it seems to me that the logical thing to do would be to set a property inside the project.yml file.