Improve release script

Add comments, auto-detect upstream remote, and update changelog

release.sh

@@ -1,3 +1,37 @@
 #!/bin/sh
 
-npm version minor && npm publish && npm version patch && git push --tags && git push origin master
+if [ -z "`which github-changes`" ]; then
+ echo "First, do: [sudo] npm install -g github-changes"
+ exit 1
+fi
+
+if [ -d .git/refs/remotes/upstream ]; then
+ remote=upstream
+else
+ remote=origin
+fi
+
+# Increment v2.x.y -> v2.x+1.0
+npm version minor || exit 1
+
+# Generate changelog from pull requests
+github-changes -o mikeal -r request \
+ --auth --verbose \
+ --file CHANGELOG.md \
+ --only-pulls --use-commit-body \
+ || exit 1
+
+# This may fail if no changelog updates
+# TODO: would this ever actually happen? handle it better?
+git add CHANGELOG.md; git commit -m 'Update changelog'
+
+# Publish the new version to npm
+npm publish || exit 1
+
+# Increment v2.x.0 -> v2.x.1
+# For rationale, see:
+# https://github.com/request/oauth-sign/issues/10#issuecomment-58917018
+npm version patch || exit 1
+
+# Push back to the main repo
+git push $remote master --tags || exit 1