fix: pubsub ack regression test - empty message
Merge pull request #307 from ryanseys/fix-pubsub

fix: pubsub ack regression test - empty message
storage: support resumable uploads
add regression test
add some unit tests
lastByteWritten -> numBytesWritten
- 5mb file, + 3 mb file
upgrade mocha + reorder tests
exponential backoff
support resumableThreshold & using simple vs resumable
better documentation
rm optional file
yelling
remove threshold
RESUMABLE_CONSTANT + resumable docs
fix
integrate md5 hash upload integrity
fix bytelength & assert.ifErrors