VOL-1460 Updated core to use voltha-protos instead of local protos
Moved protos to python directory in order to maintain functionaly of containers built there.
Added capability to do local builds of protos
Added instructions on running dep ensure for getting protos.
Updated github.com/golang/protobuf version to v1.3.1

Change-Id: Ia6ef55f07f0d5dcb5b750d7c37b21b71db85bfc4
diff --git a/vendor/github.com/golang/protobuf/ptypes/timestamp/timestamp.proto b/vendor/github.com/golang/protobuf/ptypes/timestamp/timestamp.proto
index 06750ab..eafb3fa 100644
--- a/vendor/github.com/golang/protobuf/ptypes/timestamp/timestamp.proto
+++ b/vendor/github.com/golang/protobuf/ptypes/timestamp/timestamp.proto
@@ -103,7 +103,9 @@
 // {hour}, {min}, and {sec} are zero-padded to two digits each. The fractional
 // seconds, which can go up to 9 digits (i.e. up to 1 nanosecond resolution),
 // are optional. The "Z" suffix indicates the timezone ("UTC"); the timezone
-// is required, though only UTC (as indicated by "Z") is presently supported.
+// is required. A proto3 JSON serializer should always use UTC (as indicated by
+// "Z") when printing the Timestamp type and a proto3 JSON parser should be
+// able to accept both UTC and other timezones (as indicated by an offset).
 //
 // For example, "2017-01-15T01:30:15.01Z" encodes 15.01 seconds past
 // 01:30 UTC on January 15, 2017.
@@ -114,8 +116,8 @@
 // to this format using [`strftime`](https://docs.python.org/2/library/time.html#time.strftime)
 // with the time format spec '%Y-%m-%dT%H:%M:%S.%fZ'. Likewise, in Java, one
 // can use the Joda Time's [`ISODateTimeFormat.dateTime()`](
-// http://www.joda.org/joda-time/apidocs/org/joda/time/format/ISODateTimeFormat.html#dateTime--)
-// to obtain a formatter capable of generating timestamps in this format.
+// http://www.joda.org/joda-time/apidocs/org/joda/time/format/ISODateTimeFormat.html#dateTime--
+// ) to obtain a formatter capable of generating timestamps in this format.
 //
 //
 message Timestamp {