Bump version to 3.0.0rc3 (#2367)

Also updated some dependencies, including discord.py.

Signed-off-by: Toby Harradine <tobyharradine@gmail.com>

.travis.yml

@@ -54,7 +54,7 @@ jobs:
       - echo "deb https://artifacts.crowdin.com/repo/deb/ /" | sudo tee -a /etc/apt/sources.list
       - sudo apt-get update -qq
       - sudo apt-get install -y crowdin
-      - pip install redgettext==2.1
+      - pip install redgettext==2.2
       deploy:
       - provider: script
         script: make gettext