Update Python SDK to v4 (xdevplatform#174)

* v4 Updates

* removed/updated in v4

* minor typo

* fix flake8 errors

* more flake8 fixes

* finally fixed flake8

* fix under-indented lines

Bump to version 3 (xdevplatform#162)

Include currency as a read-only campaign property (xdevplatform#145)

bump to 2.0.0 (xdevplatform#141)

Dynamic chunk size (xdevplatform#122)

For chunked uploads, choose chunk size based on

* `_RESPONSE_TIME_MAX`
* `x-response-time`

bump to 1.2.2 (xdevplatform#114)

Update __init__.py (xdevplatform#110)

New release v1.2.1

Changes:

* Various bug fixes

Enable analytics on the Campaign object (xdevplatform#104)

* Added Eclipse IDE files to .gitignore

* Enabled analytics on the Campaign object

bumping version for release (xdevplatform#66)

bump version to 1.0.0