Add lint target using package-lint

Cask

@@ -1,3 +1,6 @@
 (source melpa)
 
 (package-file "evil-collection.el")
+
+(development
+ (depends-on "package-lint"))

Makefile

@@ -5,3 +5,12 @@ compile:
 	-L .						\
 	--eval '(setq byte-compile-error-on-warn t)'	\
 	-f batch-byte-compile *.el
+
+lint:
+	cask exec $(EMACS) -Q -batch							\
+	--eval "(require 'package)"							\
+	--eval "(push '(\"melpa\" . \"http://melpa.org/packages/\") package-archives)"	\
+	--eval "(package-initialize)"							\
+	--eval "(package-refresh-contents)"						\
+	-l package-lint.el								\
+	-f package-lint-batch-and-exit *.el