Don't run main for tests

spec/spec_helper.cr

@@ -1,2 +1,7 @@
 require "spec"
-require "../src/muse-dl"
+require "../src/book"
+require "../src/parser"
+require "../src/fetch"
+require "../src/journal"
+require "../src/pdftk"
+require "../src/thing"

src/errors/invalid_link.cr

@@ -0,0 +1,4 @@
+module Muse::Dl::Errors
+  class InvalidLink < Exception
+  end
+end

src/fetch.cr

@@ -1,4 +1,5 @@
 require "crest"
+require "./errors/*"
 
 module Muse::Dl
   class Fetch
@@ -14,10 +15,10 @@ module Muse::Dl
             return Muse::Dl::Journal.new response
           end
         rescue ex : Crest::NotFound
-          raise Muse::Dl::InvalidLink
+          raise Muse::Dl::Errors::InvalidLink
         end
       else
-        raise Muse::Dl::InvalidLink
+        raise Muse::Dl::Errors::InvalidLink
       end
     end
   end

src/muse-dl.cr

@@ -3,9 +3,15 @@ require "./pdftk.cr"
 require "./fetch.cr"
 require "./book.cr"
 
+# require "./journal.cr"
+
 # TODO: Write documentation for `Muse::Dl`
 module Muse::Dl
   VERSION = "0.1.0"
 
   # TODO: Put your code here
+  class Main
+    def self.run
+    end
+  end
 end