unbound: Run test suite

Currently, there is a bug in the test suite, when building out of the
source tree. Making the test data available, in this case with a
symbolic link, works around the problem.

> When doing an out of source build of Unbound, the test suite fails
> with the error below.
>
> ```
> test signature verify functions
> testpkts error: could not open file testdata/test_signatures.1: No such
> file or directory
> Makefile:304: recipe for target 'test' failed
> make: *** [test] Error 1
> ```
>
> The reason is, that `testcode/unitverify.c` references files in a
> relative way.
>
> ```
> […]
> void
> verify_test(void)
> {
>         unit_show_feature("signature verify");
> #ifdef USE_SHA1
>         verifytest_file("testdata/test_signatures.1", "20070818005004");
> #endif
> #if defined(USE_DSA) && defined(USE_SHA1)
>         verifytest_file("testdata/test_signatures.2", "20080414005004");
> […]
> ```
>
> Unfortunately, I don’t know what the recommended way in that case is.
> Copy the test data to the build directory, link to it, or use absolute
> paths.

unbound.be0

@@ -57,9 +57,11 @@ SRCURL[0]="https://www.unbound.net/downloads/unbound-${PKGVERSION}.tar.gz"
 #    bee_configure
 #}
 
-#mee_build() {
-#    bee_build
-#}
+mee_build() {
+    bee_build
+    ln -sf ${S}/testdata ${B}/testdata
+    start_cmd make check
+}
 
 #mee_install() {
 #    bee_install