Tweak bom to reflect Spring Framework and Spring Data versions.
Remove reactive Couchbase configuration code required prior to Spring Boot 2.0 M7.
Tweak CORS examples to adapt to Spring Framework's disabled allowCredentials by default.
Add license headers. Replace CouchbaseConfiguration with Spring Boot properties. Post-process example data to make it accessible for repository use. Fix Id type. Add examples for N1ql and view access.
Enable couchbase examples in parent pom.
Add test rule to skip tests if Couchbase is not available.
Original pull request: #275.
