v2.0.0

Rustemon is now available in v2.0.0 🎉

Some major changes come with this release :

• The synchronous calls through reqwest::blocking support have been dropped
• The cache management is now handled by a middleware integrated to the reqwest client => a RustemonClient now needs to be created and passed to each calls
• Custom errors type
• NamedApiResource are now generic and can be followed to access the targeted endpoint (thanks @SteveCookTU for the idea)

Also, thanks to @irevoire and @o0Ignition0o for their reviews and advices, allowing me to improve the project and myself