MAINT: Update emperor requirement

Previously was pointing to 0.9.3 and 0.9.4-dev, now states it needs
a version greater than 0.9.5 and lesser than 1.0.0.

I also updated a link for scikit-bio.

Related to #1716
Merge pull request #1720 from ElDeveloper/emperor-0.9.5

MAINT: Update emperor requirement