chore(deps): update flask-sqlalchemy requirement from ~=2.1 to ~=2.4

[dependabot-preview]

Updates the requirements on flask-sqlalchemy to permit the latest version.

Changelog

Sourced from flask-sqlalchemy's changelog.

Version 2.4.0

Released 2019-04-24

• Make engine configuration more flexible. (684)
• Address SQLAlchemy 1.3 deprecations. (684)
• get_or_404() and first_or_404() now accept a description parameter to control the 404 message. (636)
• Use time.perf_counter for Python 3 on Windows. (638)
• Drop support for Python 2.6 and 3.3. (687)
• Add an example of Flask's tutorial project, Flaskr, adapted for Flask-SQLAlchemy. (720)

Version 2.3.3

Fix "AttributeError: 'NoneType' object has no attribute 'info'", when using polymorphic models. (#651)

Version 2.3.2

Released 2017-10-11

• Don't mask the parent table for single-table inheritance models. (561)

Version 2.3.1

Released 2017-10-05

• If a model has a table name that matches an existing table in the metadata, use that table. Fixes a regression where reflected tables were not picked up by models. (551)
• Raise the correct error when a model has a table name but no primary key. (556)
• Fix repr on models that don't have an identity because they have not been flushed yet. (555)
• Allow specifying a max_per_page limit for pagination, to avoid users specifying high values in the request args. (542)
• For paginate with error_out=False, the minimum value for page is 1 and per_page is 0. (558)

Version 2.3.0

Released 2017-09-28

• Multiple bugs with __tablename__ generation are fixed. Names will be generated for models that define a primary key, but not for single-table inheritance subclasses. Names will not override a declared_attr. PrimaryKeyConstraint is detected. (541)
• Passing an existing declarative_base() as model_class to SQLAlchemy.__init__ will use this as the base class instead of creating one. This allows customizing the metaclass used to construct the base. (546)
• The undocumented DeclarativeMeta internals that the extension uses for binds and table name generation have been refactored to work as mixins. Documentation is added about how to create a custom metaclass that does not do table name generation. (546)
• Model and metaclass code has been moved to a new models module. _BoundDeclarativeMeta is renamed to DefaultMeta; the old name will be removed in 3.0. (546)
• Models have a default repr that shows the model name and primary key. (530)
• Fixed a bug where using init_app would cause connectors to always use the current_app rather than the app they were created for. This caused issues when multiple apps were registered with the extension. (547)

Version 2.2

... (truncated)

Commits

• 2c7fde1 release version 2.4.0
• f821057 add changelog for flaskr example
• 0045123 Merge pull request #720 from pallets/flaskr
• 391c3b8 split views and models
• 7ad5738 adapt flaskr example to sqlalchemy
• da6c7cc don't require sphinx-paramrefs from sqlalchemy
• a815140 Merge pull request #718 from pallets/docs
• f994cba use pallets-sphinx-themes
• 3c96f76 Merge pull request #717 from pallets/metadata
• fcab163 reformat 2.4 changelog
• Additional commits viewable in compare view

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot squash and merge will squash and merge this PR after your CI passes on it
• @dependabot cancel merge will cancel a previously requested merge and block automerging
• @dependabot reopen will reopen this PR if it is closed
• @dependabot ignore this [patch|minor|major] version will close this PR and stop Dependabot creating any more for this minor/major version (unless you reopen the PR or upgrade to it). To ignore the version in this PR you can just close it
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
• @dependabot use these labels will set the current labels as the default for future PRs for this repo and language
• @dependabot use these reviewers will set the current reviewers as the default for future PRs for this repo and language
• @dependabot use these assignees will set the current assignees as the default for future PRs for this repo and language
• @dependabot use this milestone will set the current milestone as the default for future PRs for this repo and language
• @dependabot badge me will comment on this PR with code to add a "Dependabot enabled" badge to your readme

Additionally, you can set the following in your Dependabot dashboard:

• Update frequency (including time of day and day of week)
• Automerge options (never/patch/minor, and dev/runtime dependencies)
• Pull request limits (per update run and/or open at any time)
• Out-of-range updates (receive only lockfile updates, if desired)
• Security updates (receive only security updates, if desired)

Finally, you can contact us by mentioning @dependabot.

[codecov]

Codecov Report

Merging #6316 into development will not change coverage.
The diff coverage is n/a.

@@             Coverage Diff              @@
##           development    #6316   +/-   ##
============================================
  Coverage        65.32%   65.32%           
============================================
  Files              287      287           
  Lines            14695    14695           
============================================
  Hits              9600     9600           
  Misses            5095     5095

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update a1fae56...38654bc. Read the comment docs.