Update to voltha-tester docker image to support PPPoE client

Added PPPoE package and PPPoE client configuration to voltha-tester Docker image
for the SD-BNG use case.

Change-Id: If6ba2a8c50d021da14d2feb358c91dda7df51005
diff --git a/docker/config/pppoe-client-config b/docker/config/pppoe-client-config
new file mode 100644
index 0000000..dc63621
--- /dev/null
+++ b/docker/config/pppoe-client-config
@@ -0,0 +1,54 @@
+# Copyright 2020-present Open Networking Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Configuration file for PPP, using PPP over Ethernet
+# See the manual page pppd(8) for information on all the options.
+
+# Use the pppoe program to send the ppp packets over the Ethernet link
+# This line should work fine if this computer is the only one accessing
+# the Internet through this DSL connection. This is the right line to use
+# for most people.
+pty "/usr/sbin/pppoe -I eth0 -T 80 -m 1452"
+
+# Assumes that your IP address is allocated dynamically
+# by your DSL provider...
+noipdefault
+
+# Use this connection as the default route.
+# Comment out if you already have the correct default route installed.
+defaultroute
+
+# Override any connect script that may have been set in /etc/ppp/options.
+connect /bin/true
+noauth
+persist
+mtu 1492
+
+# RFC 2516, paragraph 7 mandates that the following options MUST NOT be
+# requested and MUST be rejected if requested by the peer:
+# Address-and-Control-Field-Compression (ACFC)
+noaccomp
+# Asynchronous-Control-Character-Map (ACCM)
+default-asyncmap
+
+hide-password
+lcp-echo-interval 20
+lcp-echo-failure 3
+
+plugin rp-pppoe.so
+nic-eth0
+nomagic
+
+user SEBA
+password rocks