allow saving records from invalid state

tests by @alexspeller
Use `package.json` as gem version
Fix to update ember-data version

Now, ember-data is versioned as 1.0.0-beta.8+canary.
Put the initialization docs back with the initializers
Update the docs on pushPayload to clarify how model is used
Merge pull request #1932 from mixonic/push-payload

Push payload
Merge pull request #1889 from tchak/invalid-save

Allow saving records from invalid state
Merge pull request #1905 from tricknotes/use-package.json-as-gem-version

Use package.json as gem version
Use SVG for the Travis badge in the README
Merge pull request #1935 from MaxGabriel/patch-1

Use SVG for the Travis badge in the README