chore(build) Use xcbeautify for TravisCI build pipeline

[surpher]

xcpretty tool does not seem to be working in our favour anymore on TravisCI when running xcodebuild commands.

Suggestion is to replace it with xcbeautify.

Changes:

• Replace xcpretty with xcbeautify for xcodebuild command,
• Remove --no-skip-current flag from the command that builds the dependencies (when pact-consumer-swift fails to build, TravisCI.org hides the output in a .log instead of printing it in build console for developer to see what has happened),
• Add a scripts/build.sh step that tests the framework builds as a Carthage dependency,
• Remove --strict from Swiftlint command to allow the bundle to build.

This PR will resolve #90.

[surpher]

Apparently TravisCI doesn't like Brewfiles on branches