phone number and email should be optional,

smash/web/models.py

@@ -74,10 +74,23 @@ class Subject(models.Model):
         verbose_name='Known languages'
     )
     phone_number = models.CharField(max_length=20,
+        null=True, 
+	blank=True,
         verbose_name='Phone number'
     )
+    phone_number_2 = models.CharField(max_length=20,
+        null=True,
+	blank=True,
+        verbose_name='Phone number 2'
+    )
+    phone_number_3 = models.CharField(max_length=20,
+        null=True,
+	blank=True,
+        verbose_name='Phone number 3'
+    )
     email = models.EmailField(
         null=True,
+	blank=True,
         verbose_name='E-mail'
     )
     date_born = models.DateField(