Added a check over tempLogFile to avoid console errors
Added a check over tempLogFile to avoid console errors

This check was added to fix an error on empty tempLogFile, the error was:
Cannot read cucumber json formatter output form C:\Users\XYZ\AppData\Local\Temp\tmp-146720bcU8JWXVv2j.tmp
[SyntaxError: Unexpected end of input]
mucsi96/nightwatch-cucumber,mucsi96/nightwatch-cucumber