Update 0000-show-updated-packages-only.md (#48)

Author: Lukas Oppermann

0000-show-updated-packages-only.md

@@ -0,0 +1,53 @@
+- Start Date: 2017-02-10
+- RFC PR: (leave this empty)
+- Yarn Issue: (leave this empty)
+
+# Summary
+
+Show only updated packages on `yarn upgrade` with the new version.
+
+# Motivation
+
+When updating I want to know which of "my" packages have been updated (not dependencies of my dependencies) so that I can verify a package has been updated to the expected version. This makes it easy to spot incorrect version constraints you define within your package.json.
+
+# Detailed design
+
+Instead of just showing all dependencies the following should be shown.
+
+```
+success Saved lockfile.    
+success Saved 774 new dependencies.    
+
+Updated direct dependencies:    
+├─ @webcomponents/custom-elements@1.0.0-alpha.3    
+├─ @webcomponents/shadycss@0.0.1    
+├─ @webcomponents/shadydom@0.0.1    
+
+All updated dependencies:    
+├─ @webcomponents/custom-elements@1.0.0-alpha.3    
+├─ @webcomponents/shadycss@0.0.1    
+├─ @webcomponents/shadydom@0.0.1    
+├─ abbrev@1.0.9    
+├─ accepts@1.3.3    
+├─ acorn-jsx@3.0.1    
+├─ acorn@4.0.11    
+├─ ajv-keywords@1.5.1    
+├─ ajv@4.11.2    
+```
+
+# How We Teach This
+
+The new section should be shown when running upgrade. Nothing else should be needed.
+
+# Drawbacks
+
+Your dependencies will be shown twice, or a `flag` needs to be introduces or the current view (showing all packages is not available / needs a flag).
+
+# Alternatives
+
+- add a flag like `--only-deps` to only show my dependencies
+- or add a flag like `--all` to show the current version
+
+# Unresolved questions
+
+-