Upgrade to Castle.Core version 4.2.0

[stakx]

This is a reminder to upgrade to the next version of Castle.Core once it's published.

One reason for the upgrade is to solve the package versioning issue discussed in #418 and castleproject/Core#288. Therefore, possibly upgrade in conjunction with #424.

/cc @skovsende, @JohanLarsson

[stakx]

Castle.Core 4.2.0 has just been published (here).

[skovsende]

Any timeframe on a release?

[stakx]

I originally would've liked to include this in 4.8.0, together with the change suggested in #424, but 4.8.0 is probably still many weeks (if not months) away. If it's important for people to have a version of Moq that depends on Castle.Core 4.2.0, then I guess we could do another patch release (4.7.x) sometime during the next 2 weeks or so.