Add a simple Makefile

.gitignore

 exa
+exa-test
 *~

Makefile

+COMPILER = rustc
+
+all:
+	$(COMPILER) exa.rs
+
+test:
+	$(COMPILER) --test exa.rs -o exa-test
+	./exa-test
+
+clean:
+	rm -f exa
+	rm -f exa-test
+
+
+