tests/int/spec.bats: simplify
tests/int/spec.bats: simplify

Most of whatever is happening in the test cases is already available in
setup_hello and teardown_hello. Use these.

Rewrite the validation test to be more compact and not dependent
on `pwd` value. Also, pinning xeipuuv/gojsonschema to a particular
version is no longer required.

Signed-off-by: Kir Kolyshkin <3a017b8ddb3f9cf3e4a59978b004111bdeb97f08@gmail.com>

xiaochenshen/runc,opencontainers/runc,dqminh/runc,estesp/runc,opencontainers/runc,rhatdan/runc,rhatdan/runc,kolyshkin/runc,opencontainers/runc,opencontainers/runc,rhatdan/runc,kolyshkin/runc,dqminh/runc,rhatdan/runc,kolyshkin/runc,xiaochenshen/runc,estesp/runc,dqminh/runc,estesp/runc,xiaochenshen/runc,kolyshkin/runc,dqminh/runc