The “FAILURES” show on Web UI is error

[superxuu]

Description of issue

The “FAILURES” show on Web UI is error .
I searched the source code,found there may have two bugs in Lib/site-packages/locust/stats.py
one is in line 279 the calculate of fail_ratio，in code is :
float(self.num_failures) / (self.num_requests + self.num_failures)
but i understand that the self.num_requests is total number of the requests, not the only the pass requests. so the correct calculate of fail_ratio may be
float(self.num_failures) / self.num_requests

The same error may happend at line 387:
fail_percent = (self.num_failures/float(self.num_requests + self.num_failures))*100

Expected behavior

the correct calculate of fail_ratio may be
float(self.num_failures) / self.num_requests

Actual behavior

TBD

Environment settings

• OS:
• Python version:3.7
• Locust version:0.11

Steps to reproduce (for bug reports)

TBD - please provide example code

[cgoldberg]

please submit a Pull Request. I can't decipher your English description of the issue.