Add support for graph-transformer plugin

[CarlinLiao]

Will close #268.

Per the tests, something seems to have broken with the apiserver initialization that could use a second look over before merging.

[CarlinLiao]

Removing that stray import fixed the major apiserver issue, but the test verifying the change to the way importance scores are indexed is still failing.

[jimmymathews]

Can you report the logs from the tests that failed?

[CarlinLiao]

I don't have them on this computer, it'll have to wait until the evening or tomorrow. It was just the apiserver importance module test though. If I recall correctly the issue was that the data object parsed from the JSON returned from the API query was empty.

I force rebuilt my data loaded images so I don't think that was the issue.

[CarlinLiao]

Upon inspection, the current implementation of GraphsAccess could potentially return multiple feature specifications. We decided that we should break out getting one feature specification as a helper function to ensure that it only comes back with one feature specification.

[CarlinLiao]

I separated the feature specification fetch in GraphsAccess so it'd always only return one or zero specifications, but I can't figure out why the test fails now.

[CarlinLiao]

All tests pass. It took like 10 or 20 minutes, but the total time at the end showed 219393s or 2.5 days, which I can assure you is a slight overestimate. This isn't the first time either.

[jimmymathews]

Tests pass for me.