[mod] optional fields in violation

bt/models.py

@@ -52,11 +52,11 @@ MEDIA = (
 class Violation(models.Model):
     country = models.CharField(max_length=2, choices=COUNTRIES)
     operator = models.CharField(max_length=256)
-    contract = models.CharField(max_length=256)
-    resource = models.CharField(max_length=20, choices=RESOURCES)
-    resource_name = models.CharField(max_length=4096)
-    type = models.CharField(max_length=20, choices=TYPES)
-    media = models.CharField( max_length=20, choices=MEDIA)
+    contract = models.CharField(max_length=256, blank=True)
+    resource = models.CharField(max_length=20, choices=RESOURCES, blank=True)
+    resource_name = models.CharField(max_length=4096, blank=True)
+    type = models.CharField(max_length=20, choices=TYPES, blank=True)
+    media = models.CharField( max_length=20, choices=MEDIA, blank=True)
     temporary = models.BooleanField( )
     contractual = models.BooleanField()
     contract_excerpt = models.TextField(blank=True)