tests: connection refactor.
datastore: datastore.key -> dataset.key doc update.

RE: 3f742eaf8946e0c42a40f148fc19ae39fa88265f missed updating the
jsdoc example code.
tests: pubsub: fix racy tests.
tests: storage: refactor + bump offset.
Reorder util.extend logic
Merge pull request #152 from ryanseys/fix-extend

Reorder util.extend logic, fixing dead code
Merge pull request #150 from stephenplusplus/test-pubsub

tests: pubsub: fix racy tests.
add back error handling.
Merge pull request #148 from stephenplusplus/connection-tests

tests: connection refactor.
datastore/request: add API error handling
datastore/request: handle API response with util.handleResp
common/util: lint
datastore/dataset: fix docstring for runInTransaction
Merge pull request #155 from proppy/fix-doc

datastore/dataset: fix docstring for runInTransaction
datastore/request: remove useless return
common/util/handleResp: only add body when non null
Merge pull request #153 from proppy/add-error-handling

datastore/request: add API error handling
Use Connection.requester and rename req to request for clarity
Clean up contributing
npm: slim down distributed files.