v1.7.0

Changelog

843428e Merge pull request #240 from scylladb/issue_229
747129d docker: default dev scylla is 4.0.0
55cbea0 gocql: bumped to v1.4.0
04a3497 gocqlx: bumped to v2.0.2
c589d97 schema: initial support for simple LWT on insert
8fd9477 schema: omitting missing schema elements when nil
123054f scripts: fixed stdin/stderr when checking scylla started