Upgraded couchbase client dependency to 3.7.2

Comment From: pivotal-cla

@ukmastercom Please sign the Contributor License Agreement!

Click here to manually synchronize the status of this Pull Request.

See the FAQ for frequently asked questions.

Comment From: pivotal-cla

@ukmastercom Thank you for signing the Contributor License Agreement!

Comment From: snicoll

Thanks @ukmastercom but, as noted in the PR template, we don't need PR for straightforward dependency upgrades like this one. I have the change already done locally but it was delayed to a build failure.