Not null the provider column on the inbound SMS table.

app/models.py

@@ -1166,7 +1166,7 @@ class InboundSms(db.Model):
     user_number = db.Column(db.String, nullable=False)  # the end user's number, that the msg was sent from
     provider_date = db.Column(db.DateTime)
     provider_reference = db.Column(db.String)
-    provider = db.Column(db.String, nullable=True)
+    provider = db.Column(db.String, nullable=False)
     _content = db.Column('content', db.String, nullable=False)
 
     @property

migrations/versions/0093_notnull_inbound_provider.py

@@ -0,0 +1,26 @@
+"""empty message
+
+Revision ID: 0093_notnull_inbound_provider
+Revises: 0092_populate_inbound_provider
+Create Date: 2017-06-02 16:50:11.698423
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '0093_notnull_inbound_provider'
+down_revision = '0092_populate_inbound_provider'
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    op.alter_column('inbound_sms', 'provider',
+               existing_type=sa.VARCHAR(),
+               nullable=False)
+
+
+def downgrade():
+    op.alter_column('inbound_sms', 'provider',
+               existing_type=sa.VARCHAR(),
+               nullable=True)