feat(err): wrap NoneError into Error

[clearloop]

Changes

• replace NoneError with Error::NoneError
• clean unused fields in models

Issues

• Closes cannot find type NoneError in module std::option #37
• Closes no function or associated item named from_str found for struct proc_macro::Literal in the current scope #45
• Closes Build fails #47

[heeh]

Awesome work!