Implement NFL Team Hierarchy

# Team Hierarchy

###### Schema 

Syntax: `http://api.sportsdatallc.org/nfl-[access_level][version]/schema/hierarchy-v1.0.xsd?api_key=[your_api_key]`

[Schema Example](http://api.sportsdatallc.org/nfl-t1/schema/hierarchy-v1.0.xsd?api_key=p94qrfyum52x5422aa9r5yd3)

###### Feed 

Syntax: `http://api.sportsdatallc.org/nfl-[access_level][version]/teams/hierarchy.[format]?api_key=[your_api_key]`

###### Parameter Format Notes

`[access_level] = Real-Time (rt), Premium (p), Standard (s), Basic (b), Trial (t)`

`[version] = whole number (sequential, starting with the number 1)`

`[format] = xml`

[Feed Example](http://api.sportsdatallc.org/nfl-t1/teams/hierarchy.xml?api_key=p94qrfyum52x5422aa9r5yd3)