fix tee2metron unit-test from starting orphan process

[shashidharatd]

We found the same thing as explained in story below happening in our environment
https://www.pivotaltracker.com/n/projects/1183596/stories/90964260

Also added a test case for permission issues also.

$ps -ef | grep chatty
$ginkgo -r tee2metron/
Running Suite: Tee2metron Suite
===============================
Random Seed: 1428032392
Will run 6 of 6 specs

••••••
Ran 6 of 6 Specs in 1.122 seconds
SUCCESS! -- 6 Passed | 0 Failed | 0 Pending | 0 Skipped PASS

Ginkgo ran 1 suite in 1.829774919s
Test Suite Passed
$ps -ef | grep chatty

previously it used to leave a couple of process running like below

$ps -ef | grep chatty
cf       118990      1  0 18:58 pts/6    00:00:01 /tmp/gexec_artifacts021681306/g314086193/tee2metron -dropsondeDestination=127.0.0.1:34275 -sourceInstance=lattice-cell-123 /tmp/gexec_artifacts021681306/g274702556/chatty_process chattyArg1 chattyArg2 -chattyFlag
cf       118993 118990  0 18:58 pts/6    00:00:00 /tmp/gexec_artifacts021681306/g274702556/chatty_process chattyArg1 chattyArg2 -chattyFlag

[#90964260]

[cfdreddbot]

Hey shashidharatd!

Thanks for submitting this pull request! I'm here to inform the recipients of the pull request that you've already signed the CLA.

[davidwadden]

this looks great! thank you for the contribution @shashidharatd