Update capsicum-test to git commit 7707222b46abe52d18fd4fbb76115ffdb3e6f74b

This includes changes to use GTEST_SKIP() instead of the local hand-rolled
mechanism as well as a few minor cleanups.

(cherry picked from commit 2d936e6c99ad1c4fb01f6c99a96dcc924ee44b9d)