Ensure the Idris code type checks

Author: yurrriq

Makefile

@@ -8,13 +8,17 @@ IDRIS ?= idris
 .PHONY: pdf site
 
 
-all: pdf site
+all: check pdf site
 
 
 build:
 	$(IDRIS) --build $(PKG).ipkg
 
 
+check:
+	$(IDRIS) --checkpkg $(PKG).ipkg
+
+
 pdf:
 	$(MAKE) -C src
 	mv src/all.pdf docs/pdf/sf-idris-2016.pdf