Naming, immutable array manipulation
Naming, immutable array manipulation

This is a sqashed version to add back the changes from #37:
- 2ab98d2b16b198c43d3c02b05662544f41d20f11
- 75ff84ad24cddeb37977241cb9419d0a1f2d5950
reactphp/http,clue-labs/http,WyriHaximus/http