~/myapp $ mkdir migrations

~/myapp $ agnostic -t postgres -u myuser -d mydb bootstrap
Migration table created.

~/myapp $ cat > migrations/add_cell_phone.sql
ALTER TABLE customer ADD cell_phone VARCHAR(255);
^D

~/myapp $ cat > migrations/add_nickname.sql
ALTER TABLE customer ADD nickname VARCHAR(255);
^D

~/myapp $ agnostic -t postgres -u myuser -d mydb migrate
Backing up "mydb" to "/tmp/tmpm8glpgaa".
About to run 2 migrations in "mydb":
 * Running migration add_cell_phone (1/2)
 * Running migration add_nickname (2/2)
Migrations completed successfully.
Removing backup "/tmp/tmpm8glpgaa".