0.14.3 Preserve unknown test plan keys + prune unlinked targets

What's Changed

• Preserve unknown test plan keys by @mikeger in #83
• Prune targets not connected to workspace by @mikeger in #84

Full Changelog: 0.14.2...0.14.3

Binary artifactbundle

.binaryTarget(
  name: "xcode-selective-test",
  url: "https://github.com/mikeger/XcodeSelectiveTesting/releases/download/0.14.3/xcode-selective-test.artifactbundle.zip",
  checksum: "4f563c76d9170c79da0e7b15a465a0f4098fca266ec060bc92cdf9595962ee34"
)