Remove the SSLv2_method:

SWIG/_m2crypto_wrap.c: In function ‘_wrap_sslv2_method’:
SWIG/_m2crypto_wrap.c:15487:3: warning: implicit declaration of function ‘SSLv2_method’ [-Wimplicit-function-declaration]

Or described here as well:

http://stackoverflow.com/questions/10547332/install-m2crypto-on-a-virtualenv-without-system-packages
http://stackoverflow.com/questions/8206546/undefined-symbol-sslv2-method