• [IMPROVEMENT] Install datadog-signing-keys package on Debian/Ubuntu. See #372.
• [IMPROVEMENT] Skip install on Linux systems when pinned version is already installed. See #371.
• [IMPROVEMENT] Update 'http' URLs to 'https' wherever possible. See #369.Thanks @rossigee.
• [BUGFIX] Detect existing version in check mode on Windows. See #364. Thanks @camjay.