Version 3.3.0 - Certifi support and improved library resolution

Changes

• CLI: Improved global errors reporting, should provide clean stack traces;
• API: When no library's path is given in version metadata, it can be guessed from the given URL (this URL must target Mojang's CDN), if no URL is provided nor based on Mojang's CDN an error is raised (thanks @ItsNiceCraft, #136) ;
• API: When certifi package is installed, it is used as Root Certificates database, which is sometimes faster than waiting for your OS' database update (thanks @slenered, #134);
• API: Added constants for common resources URLs;
• API: The download APL is finally using a memoryview in order to reduce memory allocations when downloading.