Added if statement to accommodate for couch base installation file name changes for version 2.2.0+.

For couchbase versions 2.2.0+, the file name structure has changed...

What the cookbook expects...

couchbase-server-enterprise_x86_64_2.2.0.deb

What it is now...

couchbase-server-enterprise_2.2.0_x86_64.deb

http://packages.couchbase.com/releases/2.2.0/couchbase-server-enterprise_2.2.0_x86_64.deb