Don't remove dist completely before build. Let's us remove sleep from watch:all /cc @arturi @hedgerh

bin/build-umd

@@ -16,7 +16,6 @@ OUTDIR="dist"
 TRANSFORMS="[ babelify ]"
 FLAGS="-t [ babelify ] --standalone Uppy"
 
-rm -rf $OUTDIR
-mkdir $OUTDIR
+mkdir -p "${OUTDIR}"
 
 browserify $SRC $FLAGS > $OUTDIR/$OUT

package.json

@@ -15,7 +15,7 @@
     "test:phantom": "zuul test/spec/upload.js --phantom",
     "test": "bin/test",
     "watch": "nodemon --watch src --ext scss,js -x \"npm run build && node website/update.js\"",
-    "watch:all": "parallelshell \"npm run watch\" \"sleep 1 && npm run web\"",
+    "watch:all": "parallelshell \"npm run watch\" \"npm run web\"",
     "watch:css": "nodemon --watch src --ext scss -x \"npm run build && node website/update.js\"",
     "watch:examples": "cd website && node build-examples.js watch",
     "watch:js": "nodemon --watch src --ext js -x \"npm run build && node website/update.js\"",