Migration minor improvements

backend/migrations/versions/7d27395c892a_new_migration.py

-"""empty message
+"""Initial version after history reset: Create tables and fill the "role" one
 
 Revision ID: 7d27395c892a
 Revises:
@@ -25,8 +25,8 @@ def upgrade():
         op.create_table(
             "app",
             sa.Column("id", sa.Integer(), nullable=False),
-            sa.Column("name", sa.String(length=64), nullable=True),
-            sa.Column("slug", sa.String(length=64), nullable=True),
+            sa.Column("name", sa.String(length=64), nullable=False),
+            sa.Column("slug", sa.String(length=64), nullable=False),
             sa.Column("external", sa.Boolean(), server_default='0', nullable=False),
             sa.Column("url", sa.String(length=128), nullable=True),
             sa.PrimaryKeyConstraint("id"),