Strip trailing whitespace.
Add '()' around parameter lists in method definitions.
Use '[]' instead of 'Array.new'
Convert multiline { } to do..end.
Convert double-quoted strings to single-quoted strings when there is no interpolation.
Change 'Exception' to 'StandardError'.
Remove unnecessary 'begin..end'
Remove unnecessary 'return'
Add fib action
Add '()' around parameter lists in method definitions.
Changing 'if !condition' to 'unless condition'.
Shorten multiline conditionals