Readme update for nix usage.

2 jobs for config in 4 minutes and 52 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
passed #14591
rapl
py.test

00:03:48

 
  Style
failed #14592
flake8

00:01:04

 
Name Stage Failure
failed
flake8 Style
To activate this project's virtualenv, run pipenv shell.
Alternatively, run a command inside the virtualenv with pipenv run.
$ pipenv run flake8
./nrm/daemon.py:25:1: E302 expected 2 blank lines, found 1
./nrm/daemon.py:327:32: E225 missing whitespace around operator
./nrm/daemon.py:331:43: E225 missing whitespace around operator
./nrm/daemon.py:332:18: E225 missing whitespace around operator
./nrm/daemon.py:333:16: E225 missing whitespace around operator
ERROR: Job failed: exit status 1