drop package.json, use yarn instad of npm, add build_in_docker.sh

Former-commit-id: 1f1ce1a5350eb1d4d12dc3b90bae20d6df6048f9 [formerly fae0cae6f369574aab49ab952e1aa681c97f7067] [formerly 6f8245ec50d0d2485a263e5877a6a353837b1197 [formerly f91ee24858116d7a313bdf8d57a994abbbc3f2a8]]
Former-commit-id: b9bb3ad6a460de55851943bbbc62aee74e32028c [formerly 049f6c239d7a936d70493e68f23838c0ec11af88]
Former-commit-id: 81f69427472bbeb3f82e6bd2c3a114e2c5fb47d7

build.sh

@@ -1,14 +1,25 @@
-#!/bin/bash
+#!/bin/sh
 set -e
 
+cd $(dirname $0)
+
+# Clean the dist folder and build the assets
+if [ ! -d "frontend" ]; then
+  git clone -b master https://github.com/filebrowser/frontend
+fi;
+cd frontend
+if [ -d "dist" ]; then
+  rm -rf dist/*
+fi;
+yarn install
+yarn build
+
+cd ..
+
 # Install rice tool if not present
 if ! [ -x "$(command -v rice)" ]; then
   go get github.com/GeertJohan/go.rice/rice
 fi
 
-# Clean the dist folder and build the assets
-rm -rf node_modules
-npm install
-
 # Embed the assets using rice
 rice embed-go