Add yang-cli

The original idea for this was that I would libyang C++ bindings for
this. Unfortunately, there have been problems with them as explained
here: https://github.com/CESNET/libyang/issues/1106. The easiest
solution to this was to just use the C api of libyang. After creating
some safe wrappers around pointers, it wasn't too difficult.

Change-Id: I0421cb64df66c640956501e56ffc4122eef0b9b7
diff --git a/tests/yang_access_test_vars.hpp.in b/tests/yang_access_test_vars.hpp.in
new file mode 100644
index 0000000..a23f515
--- /dev/null
+++ b/tests/yang_access_test_vars.hpp.in
@@ -0,0 +1,4 @@
+const auto exampleSchemaFile = "@CMAKE_CURRENT_SOURCE_DIR@/tests/example-schema.yang";
+const auto schemaDir = "@CMAKE_CURRENT_SOURCE_DIR@/tests";
+const auto sysrepocfgExecutable = "@SYSREPOCFG_EXECUTABLE@";
+const auto testConfigFile = "@CMAKE_CURRENT_BINARY_DIR@/test_yang_access_config";