Add Ep.VERSION

I've added an `Ep.VERSION` constant so that client code can easily check
to make sure that we're running an expected version of EPF.

  - Add `Ep.VERSION` to `lib/version.js`
  - Add test for `Ep.VERSION` to `test/version.em` which compares
    against the version provided in `package.json`.

I couldn't think of a nice way to dynamically change the value of
`Ep.VERSION` to match `package.json` without duck punching the build
process, so I've settled for a test which will fail the build if someone
forgets to bump it when they bump the version in `package.json`.
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Merge pull request #37 from jamesotron/add-ep-dot-version

Add Ep.VERSION.
Merge pull request #38 from jamesotron/add-travis-badge

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fix some embedded corner cases
fix relationship container lookups. fixes #4.
fix relationships cp type lookup
add _debugInfo to Ep.Model

useful for debugging tools such as the Chrome Ember Extension
Merge pull request #50 from jasonkriss/debug

add _debugInfo to Ep.Model
Models with missing embedded keys can now be loaded
Modified previous patch to match the comment on it
Merge pull request #63 from ginty/missing_embedded

Models with missing embedded keys can now be loaded
Clarified the meaning of update

parent.update sounds like the action that's taken by the persistence layer to persist this model. In reality, it just refers to copying values from current model into parent session's corresponding model.
Merge pull request #69 from taras/patch-3

Clarified the meaning of update