switch prerelease specifier from -rc to -beta

Author: hawkrives

fastlane/lib/util.rb

@@ -65,7 +65,7 @@ def auto_beta
   beta if last_commit != current_commit
 end
 
-def codepush_cli(app:, channel: 'nightly', install_target: '~2.2 || ~2.2.0-rc')
+def codepush_cli(app:, channel: 'nightly', install_target: '~2.2 || ~2.2.0-beta')
   target = "--targetBinaryVersion '#{install_target}'"
   # `fastlane x` runs in the ./fastlane folder, so we have to go up a level
   Dir.chdir("..") do