Split test and featureize

SplitAndFeaturize

dvc run \
    -f split.dvc \
    -d code/split_train_test.py \
    -d data/Posts.tsv \
    -o data/Posts-train.tsv \
    -o data/Posts-test.tsv \
    python \
        code/split_train_test.py \
        data/Posts.tsv \
        0.2 \
        20191001 \
        data/Posts-train.tsv \
        data/Posts-test.tsv
        
dvc run \
    -f featurize.dvc \
    -d code/featurization.py \
    -d data/Posts-train.tsv \
    -d data/Posts-test.tsv \
    -o data/matrix-train.pkl \
    -o data/matrix-test.pkl \
    python \
        code/featurization.py \
        data/Posts-train.tsv \
        data/Posts-test.tsv \
        data/matrix-train.pkl \
        data/matrix-test.pkl