This commit removes the reportfilename config parameter and adds a reportprefix parameter. AFAICT the current code suggests that it will write all host data to the same file. However the code writes the old data to the prom file giving all values -1 which is incorrect
I looked at why this was and i can't find much information on the original issue[1] and PR[2]. further to this the current implementation is very racy if one sets REPORT_FILENAME
This also updates the clean stale function to only act on files with the report_prefix and avoid deleting files which may have been placed there by none puppetserver process
more then happy to split this up into separate patches but wanted to get a bit more feedback on why things got set to -1 and if im missing something
[1]https://github.com/voxpupuli/puppet-prometheus_reporter/pull/5 [2]https://github.com/voxpupuli/puppet-prometheus_reporter/pull/7