Update PackageInfo.g

[fingolfin]

• Sebastian is no longer maintainer
• Remove Alice and Pascal, as they actually are neither authors nor maintainers (I discussed this with @aniemeyer)
• add the GAP Team as maintainer
• add homepage and source repository URLs

[codecov[bot]]

Codecov Report

Merging #42 (c119f5c) into master (f0941ec) will decrease coverage by 26.14%. The diff coverage is n/a.

@@             Coverage Diff             @@
##           master      #42       +/-   ##
===========================================
- Coverage   54.04%   27.90%   -26.15%     
===========================================
  Files           7       14        +7     
  Lines         581     2835     +2254     
===========================================
+ Hits          314      791      +477     
- Misses        267     2044     +1777     

Impacted Files	Coverage Δ
nauty27r1/naurng.c	0.00% <0.00%> (ø)
nauty27r1/naugraph.c	55.88% <0.00%> (ø)
nauty27r1/schreier.c	0.00% <0.00%> (ø)
nauty27r1/nautinv.c	0.00% <0.00%> (ø)
nauty27r1/nautil.c	38.42% <0.00%> (ø)
nauty27r1/nauty.c	54.19% <0.00%> (ø)
nauty27r1/sorttemplates.c	0.00% <0.00%> (ø)

[fingolfin]

To clarify, I only discussed removing Alice' name with Alice. But I know for a fact that Pascal also did not contribute anu code (based on discussion with him, @sebasguts and also the git log supports this).