Log Message:
Update to 1.20
Update DEPENDS

Upstream changes:
1.20      2016-04-22
	- Stable release, made in Rugby, UK during Perl QA Hackathon 2016

1.19_91   2016-04-21
	- Drop use of File::ShareDir::ProjectDistDir (GitHub #26). Thanks Kent
	  Fredric!
	- Allow stop words with '.' (GitHub #28). Thanks Paulo Custodio!

1.19_90   2016-02-20
	- Hide internals: the POD parser is moved to a private package and
	  the Pod::Spell package now only exposes the public interface.
	  This is a first step towards rewriting the parser using Pod::Simple
	  (planned for Pod-Spell-2.0).
	- 'parse_from_file' and 'parse_from_filehandle' are now explicitely
	  documented (by copying doc from Pod::Parser).