test/: Add three basic self tests

* true-001.sh: Always returns true - this should never ever fail.

* run-test-001.sh: Invokes run-test, passing itself as a parameter.
  Subsequently, it outputs the very same (hardcoded) expected and actual
  values.

* run-test-002.sh: Tests run-test's negative assertion feature in a way
  similar to run-test-001.sh. However, output different (hardcoded)
  expected and actual values and invoke run-test with the negative test
  prefix ('!').

Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>

test/run-test-001.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+if [ "$1" = 'actual' -o "$1" = 'expected' ]; then
+  echo 42
+else
+  ./run-test "$0"
+fi