fix(preamble): use upstream preamble environment detection

Dockerfile

@@ -1,4 +1,4 @@
-FROM ojkwon/arch-nvm-node:7b0d30e-node8.4-npm5.4.1
+FROM ojkwon/arch-nvm-node:6c538cc-node7.9-npm5.4.2
 MAINTAINER OJ Kwon <kwon.ohjoong@gmail.com>
 
 # Build time args
@@ -13,31 +13,12 @@ RUN pacman --noconfirm -S \
   python \
   python-setuptools \
   python2-setuptools \
-  jre8-openjdk
-# emscripten // disabled while installing pinned down version
+  jre8-openjdk \
+  emscripten
 
 # Change subsequent execution shell to bash
 SHELL ["/bin/bash", "-l", "-c"]
 
-#START emscripten--------------------------------
-# Install emscripten-1.37.18-1-x86_64.pkg.tar.xz
-# until binaryen clang failure (https://github.com/WebAssembly/binaryen/issues/1164) resolved
-
-RUN cd $TMPDIR && \
-  curl https://archive.archlinux.org/packages/e/emscripten/emscripten-1.37.18-1-x86_64.pkg.tar.xz > ./emscripten-1.37.18-1-x86_64.pkg.tar.xz && \
-  curl https://archive.archlinux.org/packages/e/emscripten/emscripten-1.37.18-1-x86_64.pkg.tar.xz.sig > ./emscripten-1.37.18-1-x86_64.pkg.tar.xz.sig && \
-  sudo pacman --noconfirm -U emscripten-1.37.18-1-x86_64.pkg.tar.xz
-
-#END emscripten--------------------------------
-
-#START preamble patch--------------------------------
-# Patch preamble.js to support Electron's renderer process with node.js environment
-# Refer https://github.com/kripken/emscripten/pull/5577 for detail.
-# TODO: remove based on upstream PR status
-COPY ./preamble.patch $TMPDIR/
-RUN patch /usr/lib/emscripten/src/preamble.js $TMPDIR/preamble.patch
-#END preamble patch--------------------------------
-
 # Initialize emcc
 RUN emcc