108536490: Initial effort to implement log in

Add endpoint for post to /sign-in
Initialise role data

migrations/versions/20_initialise_data.py

@@ -0,0 +1,16 @@
+# revision identifiers, used by Alembic.
+revision = '20_initialise_data'
+down_revision = None
+
+from alembic import op
+
+def upgrade():
+    op.bulk_insert('roles',
+                   [
+                       {'role': 'plaform_admin'},
+                       {'role': 'service_user'}
+                   ])
+
+def downgrade():
+    op.drop_table('users')
+    op.drop_table('roles')