beancount: Generate Bash completions

Author: StenAL

Formula/b/beancount.rb

@@ -56,7 +56,7 @@ def install
     virtualenv_install_with_resources
 
     bin.glob("bean-*") do |executable|
-      generate_completions_from_executable(executable, shells: [:fish, :zsh], shell_parameter_format: :click)
+      generate_completions_from_executable(executable, shells: [:bash, :fish, :zsh], shell_parameter_format: :click)
     end
   end