GetEtcdVersion performs a version check against the provided Etcd server, returning the string response, and error (if any).

IsEtcdNodeExist returns true if and only if err is an etcd node already exist error.

IsEtcdNotFound returns true if and only if err is an etcd not found error.

IsEtcdTestFailed returns true if and only if err is an etcd write conflict.

IsEtcdUnreachable returns true if and only if err indicates the server could not be reached.

IsEtcdWatchExpired returns true if and only if err indicates the watch has expired.