Fix test test_verify_sls_invalid_date
    
    Original test has a real valid eol date for bug_fixes. In
    utils.verify_sls, security_fixes and bug_fixes are iterated over to
    check the eol dates, but dict.items() iterates over in arbitrary order.
    So, when the valid bug_fixes eol date is handled, utils.verify_sls will
    continue to query PDC with the fake URL.
    
    This patch passes each invalid eol date to both security_fixes and
    bug_fixes to ensure utils.verify_sls raises expected error.
    
    Fixes #209
    
    Signed-off-by: Chenxiong Qi <cqi@redhat.com>