remove run_error from tracking code

[cmcarthur]

This branch removes the run_error field from dbt's tracking code.

It uses the new 2-0-0 version of the run_model schema.

Closes #805

[drewbanin]

One comment, but looking good to me

[drewbanin]

I think we probably also want to nix result here too, right? This would contain the exception that dbt throws if the project is misconfigured. There are a couple of instances where we pass exceptions in around here

[cmcarthur]

@drewbanin i nixed result as well. can you take a look?

[drewbanin]

LGTM if you gave this a spin and confirmed that the events were recorded

[cmcarthur]

test:

select event_id, run_error from fishtown_snowplow.run_model 
where invocation_id in ('5eb37985-587c-4004-9137-a33cbc7ff061', 'bd6142dd-5fac-4c8f-ba55-45140e166011')
limit 10;

returns:

event_id                             | run_error                                                                                                
-------------------------------------+----------------------------------------------------------------------------------------------------------
1cae9a84-181d-4d1c-8e5d-7d24672cbce7 | Database Error in model moby_dick_base (models/moby_dick_base.sql)                                       
                                     :   000904 (42000): 923491e6-b118-44c5-9ab7-7f230349f3cf: SQL compilation error: error line 5 at position 2
                                     :   invalid identifier 'ANOTHER_FIELD_THAT_DOES_NOT_EXIST'
                                     :   compiled SQL at target/run/talk/moby_dick_base.sql
9e906ecb-1daf-45d0-ba3d-8e92347dc50e |                                                                                                          

the first event is on development, second is on this branch. the invocations both have null results

[drewbanin]

@cmcarthur nice!