Update dependency flask to v1

[dev-mend-for-github-com]

This PR contains the following updates:

Package	Update	Change
flask (changelog)	major	==0.10 -> ==1.0

By merging this PR, the issue #4 will be automatically resolved and closed:

Severity	CVSS Score	CVE
High	7.5	CVE-2018-1000656
High	7.5	CVE-2019-1010083

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Release Notes

pallets/flask (flask)

v1.0

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Unreleased

v0.12.5

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Released 2020-02-10

• Pin Werkzeug to < 1.0.0. :issue:3497

v0.12.4

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Released 2018-04-29

• Repackage 0.12.3 to fix package layout issue. :issue:2728

v0.12.3

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Released 2018-04-26

• Request.get_json no longer accepts arbitrary encodings.
  Incoming JSON should be encoded using UTF-8 per :rfc:8259, but
  Flask will autodetect UTF-8, -16, or -32. :issue:2692
• Fix a Python warning about imports when using python -m flask.
  :issue:2666
• Fix a ValueError caused by invalid Range requests in some
  cases.

v0.12.2

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Released 2017-05-16

• Fix a bug in safe_join on Windows.

v0.12.1

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Released 2017-03-31

• Prevent flask run from showing a NoAppException when an
  ImportError occurs within the imported application module.
• Fix encoding behavior of app.config.from_pyfile for Python 3.
  :issue:2118
• Use the SERVER_NAME config if it is present as default values
  for app.run. :issue:2109, :pr:2152
• Call ctx.auto_pop with the exception object instead of None,
  in the event that a BaseException such as KeyboardInterrupt
  is raised in a request handler.

v0.12

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Released 2020-02-10

• Pin Werkzeug to < 1.0.0. :issue:3497

v0.11.1

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Released 2016-06-07

• Fixed a bug that prevented FLASK_APP=foobar/__init__.py from
  working. :pr:1872

v0.11

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Released 2016-06-07

• Fixed a bug that prevented FLASK_APP=foobar/__init__.py from
  working. :pr:1872

v0.10.1

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Released 2013-06-14

• Fixed an issue where |tojson was not quoting single quotes which
  made the filter not work properly in HTML attributes. Now it's
  possible to use that filter in single quoted attributes. This should
  make using that filter with angular.js easier.
• Added support for byte strings back to the session system. This
  broke compatibility with the common case of people putting binary
  data for token verification into the session.
• Fixed an issue where registering the same method twice for the same
  endpoint would trigger an exception incorrectly.

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