yanglint UPDATE print features

Added the ability to print all features in a format, which can later be
used to specify, which features a model should use, for both interactive
and non-interactive versions of yanglint.
diff --git a/tools/lint/tests/shunit2/feature.sh b/tools/lint/tests/shunit2/feature.sh
new file mode 100755
index 0000000..fb2ee88
--- /dev/null
+++ b/tools/lint/tests/shunit2/feature.sh
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+testFeature() {
+	models=( "iana-if-type@2014-05-08.yang" "ietf-netconf@2011-06-01.yang" "ietf-netconf-with-defaults@2011-06-01.yang"
+	 		"sm.yang" "ietf-interfaces@2014-05-08.yang" "ietf-netconf-acm@2018-02-14.yang" "ietf-origin@2018-02-14.yang"
+	 		"ietf-ip@2014-06-16.yang" "ietf-restconf@2017-01-26.yang" )
+	features=( " -F iana-if-type:"
+			  " -F ietf-netconf:writable-running,candidate,confirmed-commit,rollback-on-error,validate,startup,url,xpath"
+			  " -F ietf-netconf-with-defaults:" " -F sm:" " -F ietf-interfaces:arbitrary-names,pre-provisioning,if-mib"
+			  " -F ietf-netconf-acm:" " -F ietf-origin:" " -F ietf-ip:ipv4-non-contiguous-netmasks,ipv6-privacy-autoconf"
+			  " -F ietf-restconf:" )
+
+	for i in ${!models[@]}; do
+		output=`${YANGLINT} -f feature-param ${YANG_MODULES_DIR}/${models[$i]}`
+		assertEquals "Unexpected features of module ${models[$i]}." "${features[$i]}" "${output}"
+	done
+}
+
+. shunit2