5.5.0

Features:

• Add Python 3.9 support (1222). Thanks @jdufresne
• Improve formatting of long "via" annotations (1237). Thanks @jdufresne
• Add --verbose and --quiet options to pip-sync (1241). Thanks @jdufresne
• Add --no-allow-unsafe option to pip-compile (1265). Thanks @jdufresne

Bug Fixes:

• Restore PIP_EXISTS_ACTION environment variable to its previous state when resolve dependencies in pip-compile (1255). Thanks @jdufresne

Dependencies:

• Remove six dependency in favor pip's vendored six (1240). Thanks @jdufresne

Improved Documentation:

• Add pip-requirements.el (for Emacs) to useful tools to README (#1244). Thanks @jdufresne
• Add supported Python versions to README (#1246). Thanks @jdufresne