VOL-3978 - update to go 1.16

- upgraded to latest build tools that support 1.16
- specified Java source and target versions
- converted test/pom.xml to unix file format from dos

Change-Id: If2dece3a22bd247e8df8cccaac9860be8dbbe4cf
diff --git a/Makefile b/Makefile
index ef53349..968e587 100644
--- a/Makefile
+++ b/Makefile
@@ -19,7 +19,7 @@
 SHELL = bash -e -o pipefail
 
 # tool containers
-VOLTHA_TOOLS_VERSION ?= 2.0.0
+VOLTHA_TOOLS_VERSION ?= 2.4.0
 
 PROTOC    = docker run --rm --user $$(id -u):$$(id -g) -v ${CURDIR}:/app $(shell test -t 0 && echo "-it") voltha/voltha-ci-tools:${VOLTHA_TOOLS_VERSION}-protoc protoc
 PROTOC_SH = docker run --rm --user $$(id -u):$$(id -g) -v ${CURDIR}:/go/src/github.com/opencord/voltha-protos/v4 $(shell test -t 0 && echo "-it") --workdir=/go/src/github.com/opencord/voltha-protos/v4 voltha/voltha-ci-tools:${VOLTHA_TOOLS_VERSION}-protoc sh -c