* Adding Term, Field and delete_term API mapping
* Fixing test
* Fixing code doc
* Removing Term and Field and nesting code on delete_term
* Fixing lint
* Delete_documents and documentation
* Fixing style and testing exceptions
* Fixing missing return
* Fixing fmt
The new() method using pyo3 does not return self, pyo3 handles some
python magic for us instead.
Disable the clippy warning about not returning self in new since it does
not apply to us.
Damir Jelić
Paul Masurel
Ramon Navarro Bosch