Add endpoints

[jcostello93]

NOTE: there is a corresponding pull request for nba-client-template

This pull request adds 2 endpoints from the /stats namespace to the src/stats.js file:

• teamPlayerOnOffDetails
• playerCompare

It also adds 8 endpoints and modifies the schedule endpoint from the /data namespace to the src/data.js file:

• schedule (modified)
• teamSchedule
• previewArticle
• recapArticle
• leadTracker
• playoffsBracket
• teamLeaders
• teamStatsRankings
• coaches

[bttmly]

awesome! would you mind adding some basic tests for these before I merge it?

[jcostello93]

Tests should be added to the request :)

[bttmly]

Thank you!