test => 5 digits
test => simple example
Merge branch 'greatest_product_in_a_series' into master
add test into all-tests.html
test => lower case
test => upper case at first
test => upper case
test => convert all upper case
test => mixed
test => convert number
test => best practice from codewars
Merge branch 'convert_CamelCase_string_into_snake_case' into master
add test into all-tests.html