Updating composer.lock so Travis will build

Today I forked the project, enabled Travis-CLI for my fork repo and was promptly told that some of the references in .lock could not be found. Most of them were RC (release candidates) that have been removed since the last time.

I went to Packagist and confirmed that some of these had been since removed.

This is the result of me just doing a composer update to allow Travis to be able to build.