Separate exifdump into its own Package.swift #19
Description
Separate exifdump into its own Package.swift to allow running tests on iOS via xcodebuild -scheme … test for the SPM package (in short this is because there's no per-target platform choice in SPM).
See https://github.com/mz2/Carpaccio/pull/18/files#diff-3d7541c3a88f4d8bdbea8d2243071fa83c337cf991bb3c3e48b8f240861b19d7R37 for more info