Changes in version 1.17                         

    o   Check that sigma2 is larger than zero (see #21. Thanks to @elena-krismer)

                        Changes in version 1.11                         

    o   Fix copy and paste bug that meant that the wrong value was used in the unregularized 
	feature estimation procedure (see #18. Thanks to @amackey for spotting the bug).

                         Changes in version 1.3                         

    o   Escape result coefficient names if result_names() is called and they contain potentially 
	problematic characters (see issue #4)

                         Changes in version 1.1                         

    o   Only convert 0's to NA's if there are no NA's in the dataset (commit 06df44a, fix issue #3)

                 Changes in version 0.99.0 (2019-06-02)                 

    o   Initial submission