Adjustment in travis ci configs. Fix importing during first time running db upgrade

migrations/versions/59729e468045_add_view_column_to_setting_table.py

@@ -77,6 +77,11 @@ def upgrade():
 
 def downgrade():
     # ### commands auto generated by Alembic - please adjust! ###
+    ## NOTE:
+    ##  - Drop action does not work on sqlite3
+    ##  - This action touchs the `setting` table which loaded in views.py
+    ##    during app initlization, so the downgrade function won't work
+    ##    unless we temporary remove importing `views` from `app/__init__.py`
     op.drop_column('setting', 'view')
 
     # delete added records in previous version