preserve discriminator
add Alembic script for #38
stylistic change on alembic script
Merge pull request #51 from sjw0687/alembic_script_38

Missing Alembic script for #38
migration scripts are completely fixed (close #50)
test on downgrade in migration script in travis ci
Merge pull request #55 from sjw0687/fix_issue_50

Fix all of database migration scripts and add test on downgrade in CI
Created stubs for deployment strings
Kill script on non-zero exit
Show usage if no param is given
Add newline at end of the files
Use double quotes on tests
Removed executing perm
Create whl file for deployment
Add missing brackets
Use set -e instead of trap
Upload wheel file and deploy scripts
egg_info converts hyphen to underscore
Add prerequisties installation and deployment
Add Ubuntu to supported distributions