Fix for recursive down migrations

#15

Support nested folders & Postgres schema

1. Migration files generated by Hasura resides in a directory structure like

   migrations
   ├── 1111111111_one
   │   ├── down.sql
   │   └── up.sql
   └── 2222222222_two
       ├── down.sql
       └── up.sql
   

   So we need #11 to recursively find the up.sql

2. Added support to specify schema for postgres #14

3. Fix problems with make test #12

4. Ignore pq: unexpected transaction status idle error #13

Enable ssl config for cassandra

Newly supported params for cassandra

DATABASE_URL=localhost:9042?enableHostVerification=true&certPath=/file.pem&keyPath=/key.pem&caPath=/other/file.pem

See #10 for more details

fix docker build

https://hub.docker.com/r/choonkeat/dbmigrate

add Cassandra support

bumping major version because after refactoring, we are stricter on the accepted cli options for each adapter #9

Initial release

Merge pull request #8 from choonkeat/alternate-server-ready

`-server-ready` will alternate between actual db and system db connection string