Add rate-limit error

Error for exceeding the rate limit (#40)

* Add error for rate-based throttling

* Generated files

* all endpoints should be able return 429

DOSA-idl v3.3.1

Run thriftrw (#39)

DOSA 3.3

Adds a new optional field for EntityDefinition that defines the order of the columns in the table.

update copyright info

v3.2.3

build based on latest codebase (#36)

add defunct in IndexDefinition to support building flexible indexes

v3.2.2

update copyright to 2019 (#35)

fix path issue. use uber/dosa-idl but not uber-go/dosa-idl

the latest release using uber-go/dosa-idl which leads in failed update in glide. It's a terrible bug need to fix ASAP.

add columns in IndexDefinition to support building flexible indexes

modifying DOSAv2 secondary indices to support a new Columns parameter, allowing schemas to more efficiently use secondary indices. By indexing fewer columns, both read and write performance improve.

Add support for client side timestamps in DML requests

Optional client side timestamps have been added to data modifying requests to ensure correct order of operations in load balanced environments should the client desire.

DOSA 3.0

The only change from 2.0 is that Scope commands now take additional arguments.

DOSA 2.0

Tagging v2.0 in preparation for v3.0.