👷 install bundler earlier in jenkins scripts
👷 install bundler earlier in jenkins scripts

Change-Id: I0663854e8414323e76d9c6ff26442bd98f1de7b9
Reviewed-on: http://review.couchbase.org/c/couchbase-ruby-client/+/132712
Tested-by: Sergey Avseyev <87f6d5e4fd3644c3c20800cde7fd3ad1569370b3@gmail.com>
Reviewed-by: Sergey Avseyev <87f6d5e4fd3644c3c20800cde7fd3ad1569370b3@gmail.com>

couchbase/couchbase-ruby-client,couchbase/couchbase-ruby-client,couchbase/couchbase-ruby-client