Merge pull request httprunner#339 from HttpRunner/logger

replace root logger with httprunner logger

bump to v1.5.9

update test data filename

Merge pull request httprunner#321 from HttpRunner/report

1.5.7

support validate with response time

bugfix: stringfy data before generating report

record more info about request and response, and display in report

convert datetime object to string in summary data structure

display parameters and output in report

fix httprunner#269: display the former url when the current testcase …

…failed