Fixing grammatical error in why use pants doc page (#4239)
Fixing grammatical error in why use pants doc page (#4239)

### Problem

Minor grammatical error present in http://pantsbuild.github.io/why_use_pants.html

### Solution

Fixing grammatical error
lahosken/pants,15Dkatz/pants,twitter/pants,fkorotkov/pants,UnrememberMe/pants,baroquebobcat/pants,tdyas/pants,15Dkatz/pants,fkorotkov/pants,foursquare/pants,baroquebobcat/pants,pantsbuild/pants,foursquare/pants,peiyuwang/pants,twitter/pants,baroquebobcat/pants,15Dkatz/pants,UnrememberMe/pants,UnrememberMe/pants,fkorotkov/pants,UnrememberMe/pants,baroquebobcat/pants,benjyw/pants,pombredanne/pants,tdyas/pants,peiyuwang/pants,wisechengyi/pants,15Dkatz/pants,lahosken/pants,fkorotkov/pants,tdyas/pants,twitter/pants,pombredanne/pants,jsirois/pants,UnrememberMe/pants,baroquebobcat/pants,foursquare/pants,lahosken/pants,landism/pants,pantsbuild/pants,fkorotkov/pants,twitter/pants,foursquare/pants,pombredanne/pants,landism/pants,twitter/pants,tdyas/pants,lahosken/pants,peiyuwang/pants,UnrememberMe/pants,peiyuwang/pants,fkorotkov/pants,benjyw/pants,baroquebobcat/pants,UnrememberMe/pants,landism/pants,landism/pants,pantsbuild/pants,peiyuwang/pants,landism/pants,wisechengyi/pants,UnrememberMe/pants,baroquebobcat/pants,15Dkatz/pants,landism/pants,wisechengyi/pants,wisechengyi/pants,tdyas/pants,foursquare/pants,wisechengyi/pants,lahosken/pants,pantsbuild/pants,pombredanne/pants,baroquebobcat/pants,twitter/pants,pombredanne/pants,wisechengyi/pants,peiyuwang/pants,pantsbuild/pants,tdyas/pants,UnrememberMe/pants,fkorotkov/pants,foursquare/pants,15Dkatz/pants,lahosken/pants,wisechengyi/pants,twitter/pants,twitter/pants,landism/pants,pombredanne/pants,15Dkatz/pants,15Dkatz/pants,fkorotkov/pants,lahosken/pants,landism/pants,wisechengyi/pants,pantsbuild/pants,jsirois/pants,jsirois/pants,foursquare/pants,pombredanne/pants,benjyw/pants,foursquare/pants,benjyw/pants,benjyw/pants,peiyuwang/pants,pantsbuild/pants,baroquebobcat/pants,tdyas/pants,lahosken/pants,foursquare/pants,peiyuwang/pants,tdyas/pants,benjyw/pants,benjyw/pants,tdyas/pants,wisechengyi/pants,twitter/pants