Prefer GH_ENTERPRISE_TOKEN and GITHUB_ENTERPRISE_TOKEN if not a public GitHub host

[oalders]

• Prefer GH_ENTERPRISE_TOKEN and GITHUB_ENTERPRISE_TOKEN if not a public GitHub host

The enterprise tests are not using Test::Class::Moose because it seems that a skip generated by Test::Needs causes everything in the suite to be skipped. I didn't spend a lot of time on it and I'm not sure there was a lot to be gained via Test::Class::Moose for this simple test.

These results are from running the test suite as it is in this PR with an additional test class which also contains the enterprise tests.

prove -lvr t
t/enterprise.t ............
ok 1 - token
ok 2 - host found via remote
ok 3 - is a ghe host
ok 4 - Pithub args
ok 5 - token
ok 6 - token
ok 7 - no token from GH_TOKEN when URL is GHE
1..7
ok
t/run-test-class-moose.t ..
1..0 # SKIP Need xFile::pushd
skipped: Need xFile::pushd
All tests successful.
Files=2, Tests=7,  7 wallclock secs ( 0.03 usr  0.01 sys +  1.87 cusr  0.63 csys =  2.54 CPU)
Result: PASS

[PatrickCronin]

Based on rafl's review.