edit/consolidate default configuration dictionary

**Regressors:**

We include ElasticNetCV, LassoLarsCV, SGDRegressor, and RidgeCV. These are all basically linear regression. Let's remove all but SGDRegressor (or maybe ElasticNetCV). SGDRegressor can also potentially overlap with SVR. Or remove all and add sklearn.linear_model.LinearRegression

**Transformers:**
I don't think that MaxAbsScaler and MinAbsScaler are often useful, so I would argue for their removal.

Similarly, I don't think we need both RobustScaler and StandardScaler

**Classifiers:**
SGDClassifier can implement both LogisticRegression and SVC. I would keep SVC and Logistic regression and remove SGDClassifier.

related to #60