VOL-4977 - Failure in voltha-protos verification job.

Makefile
--------
 o This patch contains prototyping.
 o Define DISTUTILS_DEBUG to enable verbose output from python pkg install.
 o Define DOCKER_DEBUG to enable docker --debug.
 o Added whitespace to improve make output readability.
 o Insert banner text into targets so they will announce themselves for logging.
 o Remove @/$(HIDE) from prototype generation so command will be visible.

makefiles/docker/include.mk
---------------------------
 o Conditionally test for stdin and explicity pass --tty so docker can pass back log output.

.gitignore
----------
Ignore the virtualenv directory.

Change-Id: If73870fec03eadef2671f3f2f33075d58327914d
diff --git a/.gitignore b/.gitignore
index 1bd5b4e..8a1cfba 100755
--- a/.gitignore
+++ b/.gitignore
@@ -3,8 +3,8 @@
 *.egg-info
 dist
 build
+.venv
 .tox
-venv_protos
 
 # go related
 go_temp