Fix base() to apply font-size only once

The font-size property was being applied to both the html and body elements causing the % size reduction to occur twice, such that when font-size was set to 14px the actual type size was ~12px.
Update test for base() fix

The font-size property was being applied to both the html and body elements causing the % size reduction to occur twice, such that when font-size was set to 14px the actual type size was ~12px.
Merge pull request #137 from teddybradford/patch-1

Fix base() to apply font-size only once