pw_cli: Define Pigweed environment variables
This change adds an environment module to pw_cli which defines all of
the environment variables used by Pigweed.
A new variable named PW_USE_COLOR added, forcing the use of log colors
even if not printing to a TTY. This is set by the watch command for its
subprocesses.
The check for the PW_SUBPROCESS variable in logging is updated to use
the environment module.
Change-Id: I84007691f3ae9bb262c6bf6471afa43db831268f
diff --git a/.pylintrc b/.pylintrc
index 816add7..00c5853 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -378,7 +378,10 @@
# List of class names for which member attributes should not be checked (useful
# for classes with dynamically set attributes). This supports the use of
# qualified names.
-ignored-classes=optparse.Values,thread._local,_thread._local
+ignored-classes=optparse.Values,
+ thread._local,
+ _thread._local,
+ pw_cli.envparse.EnvNamespace
# List of module names for which member attributes should not be checked
# (useful for modules/projects where namespaces are manipulated during runtime