tests: Customize environment to run test cases

This commit minimizes the impact of running unit tests on the host
system. In particular, the test cases will have its own public info and
TPM.

Change-Id: Ic6e78ebd80dea920806ca1898caa6a2eac30348b
diff --git a/tests/wscript b/tests/wscript
index 823d25e..3b9e628 100644
--- a/tests/wscript
+++ b/tests/wscript
@@ -37,6 +37,7 @@
             source=bld.path.ant_glob(['*.cpp'], excl='main.cpp'),
             use='core-objects',
             headers='../common.hpp boost-test.hpp',
+            defines='UNIT_TEST_CONFIG_PATH=\"%s/tmp-files/\"' % bld.bldnode,
           )
 
         for module, name in {"core": "NFD Core Tests",
@@ -62,6 +63,7 @@
                 use='%s-objects unit-tests-base unit-tests-%s-main' % (module, module),
                 includes='.',
                 install_path=None,
+                defines='UNIT_TEST_CONFIG_PATH=\"%s/tmp-files/\"' % bld.bldnode,
               )
 
             if bld.env['HAVE_LIBPCAP']: