Expose ProductType, create type for build settings
Refactor Xcode functions to use BuildSettings type
Merge branch 'only-build-frameworks' into fix-multi-target-schemes
Refactor BuildSettings to load once per target
Refactor shouldBuildScheme() for multiple targets
Update platformForScheme() for multiple targets
Refactor buildScheme() to support multiple targets
Build RCL unit tests with Mac framework target

This helps test that build settings are aggregated across all targets, not just one of them (randomly).
Add empty framework built with RCL iOS scheme

Used to test that all framework targets in a scheme are built.
Log exact task invocations to stdout and stderr

Resolves #91.
Fix overlapping device/simulator builds
:fire: fixture Nimble iOS target

It apparently confuses Xcode, and is irrelevant to our tests.
Omit non-framework products from copying steps
Merge branch 'master' into fix-multi-target-schemes
Use executablePath property instead of string key
Merge pull request #146 from Carthage/fix-multi-target-schemes

Incorporate build settings from each target in a scheme