Generate proptypes validation based on breakpoints and known flexbox options

[aaronvanston]

• Move the current various Flexbox property options from their respective component into a helper function.

• Generate the prop validation based on these options and the breakpoints passed in.

• Enables dynamic validation based on the amount of breakpoints used.

[aaronvanston]

This feature is now mostly introduced with #62. All functionality is in place however there is no validation and these custom breakpoints are not stripped form the element when generating.

[billykwok]

Do you still need help? Just discovered this amazingly neat flexbox grid framework and would like to see how I could help make it fully support a dynamic number of breakpoints.

[aaronvanston]

@billykwok Thanks! Yes any help would be appreciated!

I'd like to separate out common proptype validations into files similar to the utils/helpers. These proptypes should generate based off the theme, so if a user sets an xl breakpoint etc it understands to apply the same proptype validations as the others etc