[release/v1.0] Require plain json object as metadata#442

w1am merged 5 commits intorelease/v1.0kurrent-io/KurrentDB-Client-NodeJS:release/v1.0from

cherry-pick/441/w1am/require-plain-objects-release/v1.0kurrent-io/KurrentDB-Client-NodeJS:cherry-pick/441/w1am/require-plain-objects-release/v1.0Copy head branch name to clipboard