Add new commands for DB management

[almasaeed2010]

It would be cool to have:

./tripaldock pg_dump
./tripaldock psql
./tripaldock pg_restore

[bradfordcondon]

I dont know if this counts as the same issue, but adding to this: I think we want to supply PSQL dumps that include chado with ontologies loaded, and chado with teh devseed dataset loaded. When installing ./tripaldock it should be clear how to load these (if we decide to not integrate it, then we should link to the dumps in the docks and give example setup commands)

[almasaeed2010]

DB commands added.

I'll create a new issue for a seeded database option.