Resolves: #2662

Resolves: #2996

Co-authored-by: Sébastien Eustace <sebastien@eustace.io>

Co-authored-by: Sébastien Eustace <sebastien@eustace.io>

This change adds issue triage section and additional information around
using multiple poetry versions.

Co-authored-by: Sébastien Eustace <sebastien@eustace.io>

At the moment a `poetry init` will fail, if a pyproject.toml already
exists. This change ensures pyproject.toml is reused if no build-system
has already been defined or poetry is not already configured.

Resolves: #1639

This change unifies TOML and pyproject.toml file handling to core
classes to ensure consistent handling of TOML files.

Reference: python-poetry/poetry-core#70
Reference: python-poetry/poetry-core#74

Multiple fixes for repository http authentication

This change unifies the use of authenticator for legacy repositories.
This ensures that we retrieve the correct credentials in all cases.

Relates-to: #2799 #2988

This change ensures that we use configured repositories to detect
credentials instead of `http-basic.`

Resolves: #2799

Co-authored-by: Fredrik Bergroth <fbergroth@gmail.com>

This fix allows having whitespaces in the list of extras during poetry 
add and init, e.g. `databases[postgresql, sqlite]`.

Resolves: #2980

This change ensures that invalid versions in setup files raises an 
error and gracefully fallsback to PEP 517 builds to discover package
metadata.

Resolves: #2761

The previous VERSION_REGEX string only checks for 'RC', however, the
latest RC submitted to the poetry project is '1.1.0rc1' which fails the
regex test for allowing installation of PREVIEW releases.

fixes: https://github.com/python-poetry/poetry/issues/2977

Release 1.1.0rc1

This change cleans up a few of the fixtures used in the test suite to
be more consistent and also renames ambiguous helper classes.

Resolves: #2576

Resolves: #711

provider: ensure download dest file is a string

Resolves: #98

Before this change, when .venv directory exists  within the project 
root, poetry will use it as the path to the venv regardless whether 
virtualenvs.in-project is set to true or not. This leads to confusion
as described in #1770 and #2756.

With this change poetry will check if virtualenvs.in-project is set to
true if it finds a .venv folder.

This commit also changes the default state of this configuration to be
unset (null), in order to not break any current environments.

Resolves: #1770 #2756

* changelog: fix 1.1.0b4 links

* changelog: add missing change for 1.1.0b3

Resolves: #2931