[6683] Removing unnecessary files and update gitignore

VOL-507, VOL-463: Protobuf upgrade to 3.3 and Chameleon Removal

Update the Protobuf version from 3.1 to 3.3 to alleviate
a protobuf issue when loading protobuf extensions.  The following
tests have been performed:
- Create a local Vagrant VM
- Voltha ensemble startup and check for errors/exceptions
- Manual compilations of the protos in voltha, ofagent, netconf and
chameleon directory
- Manual tests with ONOS/Voltha/Ponsim using Netconf, Curl and CLI
- Run the integration tests (known issues have Jiras already raised
against them.
- Run the make jenkins-test and make utest-with-coverage

Chameleon has been removed entirely from Voltha projects. Basic tests
have run to verify chameleon dependency has been removed.  Some
documents (like README) will need to be changed under a separate Jiras
as they are referenced in different adapters.  Some integration tests
will also need to be updated as well.

Change-Id: I2b266719a6825fb07ece3a79f7f81881ab3b9761
diff --git a/requirements.txt b/requirements.txt
index c196b4d..a2c37eb 100755
--- a/requirements.txt
+++ b/requirements.txt
@@ -25,7 +25,7 @@
 pcapy>=0.10.10
 pep8>=1.5.7
 pep8-naming>=0.3.3
-protobuf==3.1.0.post1
+protobuf==3.3.0
 protobuf-to-dict>=0.1.0
 pyflakes>=1.0.0
 pylint>=1.5.2