feat(tools): add library evolution support

[BrainCrumbz]

Hello there
hope it is ok to send an unsolicited PR.

As per title, this is in order to enable Swift library evolution support. The change in itself is really tiny.

In order to actually make everything build and run under Xcode 12 + Carthage, we had to make a number of further changes, which at the moment we decided to keep out of current PR in order not to kram everything together. We're not sure if everyone else is experiencing those problems when contributing, but we'd be happy to share those as well if library author(s) are interested.

Just for completeness, those further changes can be found in the following branches, each built on top of the previous one, and on top of current PR:

• dependency-issues
  it collects a number of issues found while trying to update Carthage private dependency, as well as while trying to build sample app and test targets
• carthage-xc12-workaround
  it collects workarounds needed to make Carthage fat frameworks work with Xcode 12

HTH

[alexiscreuzot]

merged, thanks for your work

[BrainCrumbz]

You're welcome. If interested in those further changes, we might submit two specific PRs.

[alexiscreuzot]

Absolutely, anything that improves the current state of the library is welcome