v6.3.0

Added

• Added database.version method

• Added database.login method

• Added database.exists method

• Added collection.exists method

• Added graph.exists method

• Added aql.literal function

• Exposed typings for collections and graphs (@samrg472 in #538)

Fixed

• Fixed synchronous errors during request creation not being handled

  Internal errors thrown while a request is created (e.g. malformed URIs) would
  result in unhandled errors, which could result in termination of the process
  or promises never being rejected. These errors are now handled normally and
  will result in async rejections as expected.