tests: test whether there was a compilation warning

See #1233.

algo/tests/Makefile

@@ -139,7 +139,7 @@ $(EXEC): % : %.o $(LIB)
 
 vidjil:
 	$(MAKE) -C ../ clean
-	$(MAKE) -C ../
+	$(MAKE) -C ../ 2>&1 | tee make-vidjil-algo.log
 
 core:
 	$(MAKE) -C ../core

algo/tests/should-get-tests/00-no-compilation-warning.should-get

+cat ../make-vidjil-algo.log 
+
+$ Compilation was run with -Wall
+>30: -Wall
+
+$ No compilation warning
+f0:warning
+