Add simple makefile to run all programs.

2016/Makefile

@@ -0,0 +1,18 @@
+SOLUTIONS=$(addsuffix /solution, $(wildcard day-*))
+TESTS=$(sort $(patsubst day-%/solution, test-%, $(SOLUTIONS)))
+
+.PHONY: all clean test
+
+all: $(SOLUTIONS)
+
+clean:
+	$(RM) $(SOLUTIONS)
+
+day-%/solution: day-%/solution.rs
+	rustc -o $@ $^
+
+# Utility target to run all the programs
+test: $(TESTS)
+
+test-%: day-%/solution
+	$^ $(dir $<)input.txt