BUG: Fix smaple_names being casted to int/float

read_csv was casting the `'sample_name'` column to a float if the values were
of the form `0000012.122204`, this has been fixed and we have also added a new
keyword argument to skip lines that are "empty" or that lack a sample_name i.
e. if a line starts with a `\t` character it will be ignored. Empty columns
are also now removed.
To be completely clear, this is the only way that we found was possible to ignore lines that made no sense to retain i. e. this could be a line without a `sample_name` (useless) or this could be a line where all the columns are empty (useless).