Make Method Chaining Fun

[kojix2]

Currently, ruby-htslib methods are not that easy to method chain. However, in Ruby programming, method chaining is a lot of fun, kind of like %>% in the R language.

To make this work, you need to make sure that many methods return self.

With that change, Ruby should be able to detect htslib errors.

A typical code might look like this:

def magical_method(sesame)
  r = LibHTS.hts_magical_method(sesame)
  raise "Error" if r < 0
  self
end