DI-104 Non Integer values generated in scss files

[tblacker7]

Added new function to _tools.functions:

• @function get-line-height($font-size, $line-height) Modified _tools.mixins:
• Commented out warn message line 75 for non integer and non blank values
• replaced with line 76 that generates a value based on new function

[tblacker7]

closing PR as alternative approach preferred.