esbulk 0.7.0

• set the default docType -type to the empty string

ES7 removes types (https://www.elastic.co/guide/en/elasticsearch/reference/current/removal-of-types.html), so when no -type is set, we should be good with ES7. Otherwise, ES6 and earlier require a type, so it needs to be supplied explicitly (but that was most likely the case before, too).

Since this version, we have a testcontainers-go based test setup and run basic tests on ES 5, 6, 7 (see cast).