Fix App#pack_build with no block

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## [Unreleased]
 
+## 0.1.1
+
+- Fix App#pack_build with no block https://github.com/heroku/cutlass/pull/3
+
 ## [0.1.0] - 2021-03-29
 
 - Initial release

lib/cutlass/app.rb

@@ -110,7 +110,9 @@ def pack_build
       on_teardown { build.teardown }
 
       @builds << build
-      yield build.call
+      build.call
+
+      yield build if block_given?
     end
 
     def transaction

lib/cutlass/version.rb

@@ -2,5 +2,5 @@
 
 module Cutlass
   # Version
-  VERSION = "0.1.0"
+  VERSION = "0.1.1"
 end

spec/unit/app_spec.rb

@@ -54,10 +54,14 @@ module Cutlass
             web: touch lol && tail -f lol # Need an entrypoint that doesn't exit
           EOM
 
+          # Test build with block
           app.pack_build do |result|
             expect(result.stdout).to include("Successfully built image")
           end
 
+          # Test build with no block
+          app.pack_build
+
           # App#stdout is the same as App#last_build.stdout
           expect(app.stdout).to include("Successfully built image")