added Travis-CI status to README
added Travis-CI status to README
lvminmin/lvminmin.github.com,zhanghuiguoanlige/GoogleAuthenticator,aoighost/GoogleAuthenticator,lvminmin/lvminmin.github.com,dkfiresky/GoogleAuthenticator,PHPGangsta/GoogleAuthenticator,lvminmin/lvminmin.github.com,yanniks/GoogleAuthenticator,rongzedong/GoogleAuthenticator,kevin50406418/GoogleAuthenticator,pmdevelopment/google-authenticator-bundle,RenanGaleno/PHPGoogleAuthenticator