replacing "31" with RED constant

[d-jh]

This change is

[emilio]

This looks good to me, but it seems that travis complains:

./tests/lint/trailing_whitespace.py:11:18: F821 undefined name 'RED'

You should import the constant it seems.

[aneeshusa]

@d-jh Thanks for the PR! @emilio is correct that you need to import the constant. Instead of using * to import everything, please add RED to the list of imports instead. Using the glob-style import makes it impossible to know what you're importing from where, which causes problems over time as files get bigger and definitions move around.

[jdm]

@d-jh Are you planning to finish this up?

[KiChjang]

Closing due to lack of reply for 23 days.