oracle - fixed SQL for dropping multiple columns
don't throw away the postgres client's password

broken by tgriesser/knex#390
Merge pull request #429 from nigelzor/broken-in-390

Add the password to the connection settings for Postgres

Fixes regression caused by #390
Merge pull request #428 from vschoettke/oracle-fix-drop-multiple-columns

oracle - fixed SQL for dropping multiple columns
Fix bad argument to builder.whereNull

Closes #431
oracle - fixed first and added more tests
Merge pull request #432 from vschoettke/oracle-fix-first-add-tests

oracle - fixed first and added more tests
Added CI integration for oracle