Merge pull request #122 from flutter-webrtc/renovate/random_string-2.x

Update dependency random_string to v2

Author: cloudwebrtc

pubspec.yaml

@@ -12,7 +12,7 @@ dependencies:
  parser_error: ^0.1.1
  sdp_transform: ^0.2.0
  uuid: ^2.0.2
- random_string: ^1.1.0
+ random_string: ^2.0.0
  logger: ^0.9.0
  intl: ^0.16.0
  recase: ^3.0.0