fix for tag install issue

[bueche]

Description

the npm install command did not like the package.json syntax for supporting 15 and 16 versions of graphql. this didn't show up in all of the tests until I did a manual install of the pushed join-monster v 3.3.0. this patches the problem by only supporting version 16.

The error looks as follows:

c889f3bd2e05 test-proj % npm install join-monster      
npm ERR! code EINVALIDTAGNAME
npm ERR! Invalid tag name "^16.0.0|^15.4.0" of package "graphql@^16.0.0|^15.4.0": Tags may not have any characters that encodeURIComponent encodes.

• [x ] This change adds test coverage for new/changed/fixed functionality

Checklist

• [x ] I have added documentation for new/changed functionality in this PR via comments and by updating the change log