Adding atom tests and makefile

Makefile

@@ -0,0 +1,13 @@
+default: build-release
+
+build-release:
+	cargo build --release
+
+test:
+	cargo test --release
+
+install: build-release
+	mkdir -p ${HOME}/.config/mal
+	cp -f core/core.mal ${HOME}/.config/mal/
+	sudo cp target/release/rust-mal /usr/local/bin/mal
+	sudo chown ${USER} /usr/local/bin/mal

tests/atoms.mal

@@ -4,3 +4,16 @@
 
 ; deref
 (assert-eq (deref (atom 1)) 1)
+
+; @ macro
+(assert-eq @(atom 1) 1)
+
+(def! ATOM (atom 1))
+
+; reset!
+(reset! ATOM 2)
+(assert-eq @ATOM 2)
+
+; swap!
+(swap! ATOM (fn* [x] (* x 2)))
+(assert-eq @ATOM 4)