Add space for left button too (#96)

I don't add the margin to the button as default-btn is also used when such a margin is unnecessary

css/bootstrap/zerobin.css

@@ -36,10 +36,16 @@ body.navbar-spacing {
 	margin-left: -56px;
 }
 
+/* add space around buttons */
+
 .btn-primary {
 	margin-left: 8px;
 }
 
+.dropdown > #expiration {
+	margin-left: 8px;
+}
+
 #image img {
 	max-width: 100%;
 	height: auto;