0.1.0-rc5

• Improved logging for Verbose Learners
• Added max document frequency to Word Count Vectorizer
• Whitespace Trimmer is now a separate Transformer
• Text Normalizers no longer remove extra whitespace
• Added extra characters pattern to Regex Filter class constants
• Moved Lambda Function transformer to Extras package
• GaussianNB new class labels during partial train
• Decision Tree print ruleset now accepts a header
• Fixed Variance Threshold Filter drop categorical by default
• Removed AdaBoost return learned sample weights