Create a Test for AutoMPG dataset

[mvnural]

This is the first step of running models from input specification. The data/metadata extraction may be completely manual for now.
Steps

1. Add a new test to ModelClassifier and read data and metadata
2. Construct a Model object and add all available metadata. This depends on Create a model class #21 .
3. Run suggested models and obtain fitness and extra information to be added such as residual distribution. (Code Generation)

[mepcotterell]

I'm going to go ahead and accept this. However, we will need to discuss more on #21 before continuing with this issue.