Bump version number to v1.4.2
Bump version number to v1.4.2

Motivation
----------
Altering the way that versions are managed so that version numbers
are bumped just after tagging rather than just before. Doing
this makes it more clear which version a change belongs to as
changes will be made against the version that will become the tag.

Change-Id: I33dc10b151cf690c5c7ef9d418acd2651f17659c
Reviewed-on: http://review.couchbase.org/98935
Reviewed-by: Brett Lawson <c8c4369773d7d7226e031f0c4af62e3f38a08510@gmail.com>
Tested-by: Charles Dixon <e13bf4498b4994e133fd3586350658dc4a59329a@gmail.com>

brett19/gocb