0.8.1

Fix cohere tokenizer test #307
Fix upsert on gcp starter indexes #308
Stop calling with unused preamble_override param to cohere chat [#315]#315)
Example for specifying and encoder to KB in README #302 (Thanks @coreation!)
Remove JINA API key from mandatory env vars #303 (Thanks @aulorbe!)
Full Changelog: v0.8.0...v0.8.1