Added missing type checks for constants.

src/type_checkers/component.cr

@@ -5,6 +5,7 @@ module Mint
       resolve node
 
       resolve node.gets
+      resolve node.constants
       resolve node.functions
 
       VOID

src/type_checkers/module.cr

@@ -2,6 +2,7 @@ module Mint
   class TypeChecker
     def check_all(node : Ast::Module) : Checkable
       resolve node
+      resolve node.constants
       resolve node.functions
 
       VOID

src/type_checkers/suite.cr

@@ -1,8 +1,9 @@
 module Mint
   class TypeChecker
     def check(node : Ast::Suite)
-      resolve node.name
+      resolve node.constants
       resolve node.tests
+      resolve node.name
 
       VOID
     end