This change ensures that packages that only have a pre-release versions
are pragmatically discovered via `find_packages` when a constraint (*)
is specified.

Resolves: #2819

The existing example:
```bash
poetry export -f requirements.txt > requirements.txt
```
The problem with this is that any additional output from poetry will also end up in the requirements file. For instance, if the `poetry.lock` file is not present, poetry will output to stdout some extra text telling you about this. This breaks the requirements file. (I was burned by this problem, hence this PR)

Seeing as there is already a documented option to specify the filename directly, which resolves this issue, updating the docs like this seems reasonable.

* Add note for setting up poetry in a pre-existing project.

Resolves: #2630

* Show poetry init in more detail

* Update docs to reflect real poetry init usage

This change ensures that the executor does not deadlock on IO errors,
for example when IO does not support non-ascii characters.

Misc. clean up: Development dependencies, doc build action, tox for doc builds, pre-commit hook updates (#2814)

* docs: move build dependencies to tox environment

* provider: mark wheel as unsafe package

* Fix tox default configuration

* pre-commit: update hooks

* actions: add workflow for doc sanity build

* isort: update configuration to v5

* flake8: fix issues

* Update pyproject.md

Explain that `poetry install` installs the scripts in the virtualenv. See #2179 for the use case.

read package name from pypi info .info.name
close #2098

Resolves: #2333

Prior to this change, when checking solver results the tests cases
relied on the weaker equality check of the `Package` class. With
python-poetry/poetry-core#53, the check has been made stricter.

This change, while having no functional impact, ensures that once
poetry-core is updated, tests do not fail unexpectedly.

This works around a glob parsing bug in cirrus-ci.

Relates-to: cirruslabs/cirrus-ci-docs#696

Relax tomlkit version requirement

Co-authored-by: Arun Babu Neelicattu <arun.neelicattu@gmail.com>

Improve detection of installed packages in an environment

* ci: artifact release automation for freebsd

Resolves: #2309

* ci: limit python versions to 2.7 and 3.7 (freebsd)

* ci: ignore action checks for cirrus only change

A package installed from git is sometimes mistaken as a standard
package since it has a `.dist-info` directory. This change ensures
that the pth file sources are also taken into consideration when
determining if a package is git sourced.

Additionally, this change ensures that a pth file is searched for in
both platlib and purelib site directories.

When detecting installed packages, ensure that we check both purelib
and platlib site directories when determining if a package is a
standard package.

Cached artifact uri was previously constructed manually using a string
representation of the artifact path. This change ensures that the uri 
is generated by pathlib instead.

Resolves: #2744

Co-authored-by: Fredrik Averpil <fredrik.averpil@ericsson.com>
Co-authored-by: Arun Babu Neelicattu <arun.neelicattu@gmail.com>

This change ensures that non fancy io can use parallel installs.

Release 1.1.0b2

Release 1.1.0b1

Display logging messages from poetry-core when building