better errors and cleanp

tests/fullslime/build.sh

@@ -0,0 +1,11 @@
+echo ""
+echo "----------------------"
+echo "  compiling libslime  "
+echo "----------------------"
+echo ""
+
+clang++ --std=c++17      \
+        main.cpp -o main \
+        -I../../3rd/     \
+        -I../../src/     \
+        -I../../include/ \

tests/fullslime/main.cpp

@@ -0,0 +1,6 @@
+#include <libslime.cpp>
+
+int main() {
+    int res = Slime::run_all_tests();
+    return res ? 0 : 1;
+}