refactor: refactor test functions and remove unused variables

[appleboy]

• Remove the runArgs variable
• Change the way flag.CommandLine.Parse is called
• Modify the TestBinCmdPath function
• Modify the TestConfigWithRuntimeArgs function
• Modify the TestCtrlCWhenHaveKillDelay function
• Modify the include_file value in the TestCtrlCWhenHaveKillDelay function
• Modify the include_file value in the TestConfigRuntimeArgs function
• Modify the TestFlag function
• Modify the TestConfigRuntimeArgs function
• Modify the Test_killCmd_SendInterrupt_false function
• Modify the bytesRead variable in the Test_killCmd_SendInterrupt_false function

also fix https://github.com/cosmtrek/air/pull/439

[appleboy]

Any feedbacks? @xiantang

[xiantang]

will check

[appleboy]

@xiantang all done https://github.com/cosmtrek/air/pull/476/commits/21652ecf23c7a97c7e176e23f621a515caaefcf2