[Test] Add missing specs for Charge resource

[erick-tmr]

• Added all missing specs for methods that belongs to Charge resource
• Added shared examples for all the CRUD actions
• Added shared examples to Charge resource
• Added more exclusion rules to Rubocop configs
• Extracted body formatter class
• Added succes? alias method to ApiResponse class
• Minor fixes to docs
• Fixed set_pagination method from Resource class to set default values corretcly
• Specs for ApiResponse class
• Specs for Client class
• Specs for HttpClient class
• Configure Rspec to run at random order