Don't use sed to edit gitignore in release.sh

sed -i is not cross-platform.

.gitignore

@@ -1,12 +1,9 @@
-build/
 .DS_Store
 node_modules/
 npm*
 src/compression/
 test/lib/
 dist/
-dist/*.tgz
-dist/*_debug.js
 openpgp.store/
 doc/
 browserify-cache*.json

release.sh

@@ -24,10 +24,8 @@ npm run build
 grunt test
 
 # Add build files to git
-sed -i "" '/^dist\/$/d' .gitignore
-git add dist/ bower.json npm-shrinkwrap.json package.json
+git add --force dist/ bower.json npm-shrinkwrap.json package.json
 git commit -m "Release new version"
-git checkout .gitignore
 git tag v$1
 git push
 git push --tag