Singular form of words ending in 'our' and in 'lives' are incorrect

[emilhdiaz]

Example:
Python 2.7.9 (default, Feb 10 2015, 03:28:08)
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.56)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
$> from pattern.en import singularize
$> singularize('flour')
'flmy'
$> singularize('colour')
'colmy'
$> singularize('your')
'ymy'
$> singularize('olives')
'olife'

#176 #175