Specify project_directory

[Reedyuk]

I currently have a workspace project with nested projects which all have carthage dependancies.
I currently do this:

carthage(platform: 'iOS', project_directory: './Frameworks/SubProjOne', cache_builds: true)
carthage(platform: 'iOS', project_directory: './Frameworks/SubProjTwo', cache_builds: true)
carthage(platform: 'iOS', project_directory: '"./Applications/MainProj"', cache_builds: true)

I am trying to use the fastlane plugin for rome but i am unable to run rome in the different project directories. I would need something similiar to how i call carthage in fastlane e.g. project_directory

At the moment i have had to default back to doing this in my fastfile.
sh('cd "../Applications/MainProj" && rome download --platform iOS --cache-prefix Swift5')
sh('cd "../Frameworks/SubProjOne" && rome download --platform iOS --cache-prefix Swift5')
sh('cd "../Frameworks/SubProjTwo" && rome download --platform iOS --cache-prefix Swift5')

[tmspzz]

Sounds good, feel free to submit a PR for this 👍