WIP use the active context
Failing spec for yielding fiber
Preserve the context chain across yields
Save/resume the CLS context chain
Reuse the chain on save/resume

Avoids an array copy each time the fiber yields
Reorg tests to better enumerate cases
Use a state/transition based model

Allows us to distinguish between a fiber being run for the first time
(run) vs. resuming (resume) and yielding (yield) vs ending (end). Each
has a different behavior in regards to CLS.
Remove peer dependency on continuation-local-storage
Add assertions

Save active context at fiber creation rather than fiber run.
1.1.0
Merge pull request #6 from goodeggs/preserve-continuation-chain

Preserve continuation chain