v0.5.0

• Adds concurrency to speed up validating proxies. This brings finding a valid proxy from ~1.5 minutes down to just ~4-20 seconds depending on the available proxies at the time
• Bumps thread count from 10 to 20
• Bumps timeout to validate a proxy from 0.5 to 1 second with no filters and 3 to 2 seconds with filters
• Exposes list_proxies and validate_proxy functions which were previously internal
• Adds timers to test results and brings coverage to 100%