[TOOLSLIBS-619] Release prep 6.1.0 (#202)

* updates version and changelog

* rm unused imports

* formatting fix

v6.0.1 - Adds backoff to setup (#195)

* adds backoff to setup

* bumps version

[TOOLSLIBS-514] Release prep for 6.0.0 (#194)

* updates changelog and version

* adds bearer token, cleans up removals

* new things

* adds type annotation changelog

* review cleanup

* removes py27 from testing requirements in PR template!

* readme updates for 6.0

* adds custom_events module to setup

[TOOLSLIBS-406] 5.7.0 release prep (#185)

* adds recent updates

* moves to tools team

* adds new versions, text cleanup

* adds 3.10 to testing versions

* adds new py version

* rm 3.10

* stringifies and re-adds 3.10

* adds recurring schedule things

* rm 3.10 for new

* adds scheduled push validate

* typo and clarity

* adds localization

* subscription list things

* adds attribute list and static list changes

* add new py version

* typo fix

[TOOLSLIBS-403] Deprecations for version 6.0 (#170)

* adds deprecation warnings

* adds deprecation warnings

* typos

* proper Python

Merge pull request #162 from urbanairship/TOOLSLIBS-354-appkey-header

[TOOLSLIBS-354] Adds App Key to user agent string

Merge pull request #159 from urbanairship/TOOLSLIBS-316

TOOLSLIBS-316 Added Tag Groups to Push Audience

update changelog and version (#158)

Merge pull request #156 from urbanairship/5.4.0-release-prep

5.4.0 release prep

Merge pull request #152 from urbanairship/experiment-validate-fix

Experiment validate fix