Update scout_apm to 2.3.0

[pyup-bot]

This PR updates scout_apm from 2.0.1 to 2.3.0.

Changelog

2.3.0

Added

- Use Django's native DB instrumentation on Django 2.0+, rather than monkey
patching the database cursor.
([PR 218](https://github.com/scoutapp/scout_apm_python/pull/218)).

Fixed

- Fix tracking of path on Flask.
([PR 221](https://github.com/scoutapp/scout_apm_python/pull/221)).

2.2.1

Fixed

- Close file descriptors when launching the core agent process. This fixes a
bug where uwsgi's HTTP ports would be held by the it on Python 2.7.
([PR 219](https://github.com/scoutapp/scout_apm_python/pull/219)).

2.2.0

Added

- Track user IP on Flask
([PR 190](https://github.com/scoutapp/scout_apm_python/pull/190)).
- Make user IP tracking on Bottle and Pyramid use the same algorithm as other
integrations, checking for the `client-ip` header
([PR 192](https://github.com/scoutapp/scout_apm_python/pull/192),
[PR 195](https://github.com/scoutapp/scout_apm_python/pull/195)).
- Add support to Bottle, Falcon, Flask and Pyramid integrations for tracking
request queue timing
([PR 199](https://github.com/scoutapp/scout_apm_python/pull/199),
[PR 201](https://github.com/scoutapp/scout_apm_python/pull/201)).

Fixed

- Track path and user IP on Django < 1.10
([PR 190](https://github.com/scoutapp/scout_apm_python/pull/190)).
- Fix the undocumented `core-agent-manager` CLI command
([PR 202](https://github.com/scoutapp/scout_apm_python/pull/202)).
- Consistently track view responses on Django between different versions
([PR 203](https://github.com/scoutapp/scout_apm_python/pull/203)).
- Avoid unbalanced request tracking in certain cases on Django < 1.10
([PR 203](https://github.com/scoutapp/scout_apm_python/pull/203)).
- Clarified contents of public API by moving some stuff out of it and setting
`scout_apm.api.__all__`
([PR 204](https://github.com/scoutapp/scout_apm_python/pull/204)).

2.1.0

Added

- Add support to Django integration for tracking request queue timing from the
value of the `X-Queue-Start` or `X-Request-Start` header
- Add Falcon integration

2.0.5

Added

- Tested on Django 2.2
- Added PyPI Trove classifiers for frameworks
- Track usernames on Django < 1.10

Fixed

- Stop warnings from using deprecated method `logger.warn`
- Track some missed requests on Flask such as automatic `OPTIONS` responses

2.0.4

Fixed

- Fix 'ignore' functionality on Django < 1.10

2.0.3

Added

- Add 'scm_subdirectory' config option (PR 155)

Fixed

- Fixed Elasticsearch integration for queries passing 'index' to `elasticsearch-py` as a list (PR 156)
- Fixes "Registering with app" log message not using configured logger (PR 154)

2.0.2

Added

- Add platform triple to config (PR 151)

Links

• PyPI: https://pypi.org/project/scout-apm
• Changelog: https://pyup.io/changelogs/scout-apm/
• Repo: https://github.com/scoutapp/scout_apm_python