Merge pull request #25 from minor-fixes/update_deps

go: Update all dependencies, imports

Merge pull request #23 from google/mod-update

support go1.15+

Merge pull request #17 from yarelm/flush

feat: add close method to sink

Merge pull request #14 from google/update-deps

deps: update dependencies

Merge pull request #7 from google/better-test

Test Coverage

Merge pull request #1 from kalafut/update-google-dep

Update cloud.google.com version