Install missing mypy stubs

[thopre]

Summary

Mypy currently warns about missing stubs to analyse LNT's code:
lnt/server/ui/globals.py:5: error: Library stubs not installed for
"flask" (or incompatible with Python 2.7)
lnt/server/ui/decorators.py:1: error: Library stubs not installed for
"flask" (or incompatible with Python 2.7)
lnt/lnttool/convert.py:2: error: Library stubs not installed for "click"
(or incompatible with Python 2.7)
lnt/lnttool/common.py:2: error: Library stubs not installed for "click"
(or incompatible with Python 2.7)
lnt/lnttool/import_report.py:1: error: Library stubs not installed for
"click" (or incompatible with Python 2.7)
lnt/lnttool/admin.py:4: error: Library stubs not installed for "click"
(or incompatible with Python 2.7)

This commits adds the necessary dependency to get rid of those warnings.

[PrzemekWirkus]

LGTM

[cmatthews]

In recent versions of mypy, they have a --install-types flag which can do this automatically.

http://mypy-lang.blogspot.com/2021/06/mypy-0900-released.html

[thopre]

In D104706#2833564, @cmatthews wrote:

In recent versions of mypy, they have a --install-types flag which can do this automatically.

http://mypy-lang.blogspot.com/2021/06/mypy-0900-released.html

That's what I used for getting this list but it was asking me to confirm installation and I did not know of a way to disable it. I'm happy to revert this diff if there's a way to force installation.

[PrzemekWirkus]

From what I can see mypy version 0.910 (From yesterday) has new option --non-interactive:

See http://mypy-lang.blogspot.com/2021/06/mypy-0910-released.html
"This release adds the new option --non-interactive that can be used with --install-types to install suggested stub packages without asking for confirmation. "

I guess adding info about above to README would be a nice to have.

[thopre]

In D104706#2835465, @PrzemekWirkus wrote:

From what I can see mypy version 0.910 (From yesterday) has new option --non-interactive:

See http://mypy-lang.blogspot.com/2021/06/mypy-0910-released.html
"This release adds the new option --non-interactive that can be used with --install-types to install suggested stub packages without asking for confirmation. "

I guess adding info about above to README would be a nice to have.

Great, then I'll prepare a patch to use that instead. Thanks!

tox.ini

commands =
     lit -sv ./tests/
 
 [testenv:mypy]
 basepython = python3
 skip_install = true
 deps =
     mypy
     sqlalchemy-stubs
+    types-Flask
+    types-Jinja2
+    types-PyYAML
+    types-Werkzeug
+    types-click
+    types-pkg_resources
 commands =
     # No where close to passing yet, but nice to have.
     - mypy --junit-xml=junit-{envname}.xml --py2 --ignore-missing-imports lnt
     - mypy --junit-xml=junit-{envname}.xml --ignore-missing-imports lnt
 
 [testenv:flake8]
 skip_install = true
 deps =