* Modify if statement
Change the solution so an empty string is returned when num is less than 1 rather than less than 0 for consistency with instructions.
* Add test
New test checks that if num is 0, an empty string is returned
* Fix test
Fixing errors in newly proposed test that checks that empty string is returned when num is 0
* Modify intermediate solution
Changing if statement in intermediate solution to check whether num is less than 1 rather than less than 0. (Also adding curly brackets to that solutions if/else statements.)
* fix: removed unnecessary assert message arguments
