Add support for redshift.

Create a common class for redshift and postgres (since they are similar).
In the future postres should more to contrib as well.
Create both a Redshift target and an S3CopyTask
Support for AutoConfigClient from snakebite.client
Add basic testing for the mysql target
Remove the doc that describes the setup. Setup is automated now
Use postgres as the Target for both Redshift and Postgres (only add an attribute use_db_timestamps). And rename postgreslike to rdbms
fix HdfsClient.mkdir to create ancestors
Adds upstream dependencies option to visualizer

Uses new api call /api/inverse_dep_graph/<task_id>, which returns
the same data types as  /api/dep_graph, except the "deps" field
is inverted.

E.g. If A requires B, the data returned is
{
  "B()": {
     deps: ["A()"]
  }
}
Add test, fixes from test

Inverse dependency wasn't being added if we'd already seen it
Move n_reduce_tasks hadoop config logic into JobTask

This fixes a (somewhat severe) bug where non-streaming jobs (i.e., jobs
in jars) would have their hadoop config set to 0 reduce tasks.
Fix the partition exists check so it matches the table exists code above.  Without this the check will always fail if the partition doesn't exist yet due to the underlying command returning a non-zero result
Merge pull request #292 from jmeagher/partition-exists-fix

Fix the partition exists check so it matches the table exists code above...
Merge pull request #291 from a1k0n/master

Move n_reduce_tasks hadoop config logic into JobTask
Merge pull request #283 from rantav/mysql

Add basic testing for the mysql target
leave HdfsClientCdh3.mkdir behavior intact
Merge pull request #287 from spotify/uldis/ancestors

fix HdfsClient.mkdir to create ancestors
- fix serialization of DataHourParameter when the value is None
Merge pull request #293 from JonNelson/fix_date_hour_param

- fix serialization of DataHourParameter when the value is None
Merge pull request #276 from rantav/redshift

Add support for redshift.
Merge pull request #288 from JoeEnnever/upstream

Adds upstream dependencies option to visualizer
Merge pull request #284 from kawaa/autoconfig-snakebite

Support for AutoConfigClient from snakebite.client