refactor: move languages from branch worker to manager (#1044)

lib/manager/docker/update.js

lib/manager/index.js

lib/manager/meteor/update.js

lib/manager/npm/update.js

lib/workers/branch/index.js

lib/workers/branch/package-files.js

test/manager/docker/__snapshots__/update.spec.js.snap

test/manager/docker/update.spec.js

test/manager/index.spec.js

test/manager/meteor/__snapshots__/update.spec.js.snap

test/manager/meteor/update.spec.js

test/manager/npm/update.spec.js

test/workers/branch/index.spec.js

test/workers/branch/package-files.spec.js