v1.15

feat(meta): handle comma-separated version

deps: upgrade to scrapy 2.2.1 and chrome to stable 84

feat: update chrome to 83.0.4103.61

feat(meta): do not jsonized version meta

feat: avoid indexing element with empty current_level

feat: remove no linking anchor

feat(analytics): define a consistent ObjectID

feat(headless_chrome): use google chrome 78

build(dockerignore): add .dockerignore to prevent sharing sensitive d…

…ata or useless files into the docker image algolia#494