New UserAgents

CheckMarkNetwork/1.0 (+http://www.checkmarknetwork.com/spider.html)
httpx - Open-source project (github.com/projectdiscovery/httpx)
NetSystemsResearch studies the availability of various services across the internet. Our website is netsystemsresearch.com
Expanse indexes the network perimeters of our customers. If you have any questions or concerns, please reach out to: scaninfo@expanseinc.com
Go http package