add error handling for filesize and gunzipped size, ref mapbox/tilestream-pro#2885
add project.xml size validation
remove 'validation' err type
throw RangeErrors
add nodirectory test
move fixtures to .tm2z files
add streamsize error tests
replace duplicate nodir test with doublezip
add custom size error support and tests, ref #20
Merge pull request #20 from mapbox/error-streamsize

Throw validation errors if uploads are too large