Added twitter and github sign-in buttons; reduced button sizes

public/css/app.css

@@ -58,3 +58,4 @@ h3 {
   text-align: center;
   line-height: 300%;
 }
+

views/login.jade

@@ -7,13 +7,22 @@ block content
       a(href='/signup') Sign Up
     .row
       .col-xs-6.col-sm-6.col-md-6
-        a.btn.btn-lg.btn-primary.btn-block(href='/auth/facebook')
-          i.fa.fa-facebook-square
-          |  Facebook
+        a.btn.btn-primary.btn-block(href='/auth/facebook')
+          i.fa.fa-facebook
+          |   Facebook
       .col-xs-6.col-sm-6.col-md-6
-        a.btn.btn-lg.btn-danger.btn-block(href='/auth/google')
-          i.fa.fa-google-plus-square
-          |  Google
+        a.btn.btn-danger.btn-block(href='/auth/google')
+          i.fa.fa-google-plus
+          |   Google
+    .row
+      .col-xs-6.col-sm-6.col-md-6
+        a.btn.btn-info.btn-block(href='/auth/twitter')
+          i.fa.fa-twitter
+          |   Twitter
+      .col-xs-6.col-sm-6.col-md-6
+        a.btn.btn-default.btn-block(href='/auth/github')
+          i.fa.fa-github
+          |   GitHub
     .login-or
       hr.hr-or
       span.span-or or