1024-bit rsa keys,  Darwin,  expiration_days

generate 1024-bit rsa keys,  
do not treat Darwin specially in this respect, as openssl is there anyway, 
decrease expiration_days to an acceptable period.
Merge pull request #118 from dimpase/patch-2

1024-bit rsa keys,  Darwin,  expiration_days
Version bump to 0.10.5