Update bootstrap to install Swift on Linux

bin/bootstrap

@@ -1,16 +1,23 @@
-#!/bin/sh
+#!/bin/bash
 
-# bail on errors
-set -e
+# bail on errors and unset variables
+set -euo pipefail
 
-# export PATH="$HOME/.rbenv/shims:$PATH"
+SWIFT_VERSION=5.1.3
+SWIFT_DIR=swift-$SWIFT_VERSION-RELEASE/swift-$SWIFT_VERSION-RELEASE-ubuntu18.04
+SWIFT_FILENAME=$SWIFT_DIR.tar.gz
 
-echo "*** bootstrap samhuri.net"
-
-echo "* bundle install"
-bundle install
-
-# echo "* npm install"
-# npm install
+if [[ $(uname) = "Linux" ]]; then
+  if which swiftc >/dev/null 2>/dev/null; then
+    echo "*** swift is installed: $(swift --version)"
+  else
+    echo "*** installing swift"
+    pushd $HOME
+    wget https://swift.org/builds/swift-$SWIFT_VERSION-release/ubuntu1804/$SWIFT_FILENAME
+    tar xzf $SWIFT_FILENAME
+    echo "export PATH=\"\$HOME/$SWIFT_DIR/usr/bin:\$PATH\"" >> $HOME/.bashrc
+    popd
+  fi
+fi
 
 echo "*** done"

bin/build-gensite

@@ -3,9 +3,9 @@
 set -euo pipefail
 
 if [[ $(uname) = "Linux" ]]; then
-    build_platform_dir="x86_64-unknown-linux"
+  build_platform_dir="x86_64-unknown-linux"
 else
-    build_platform_dir="x86_64-apple-macosx"
+  build_platform_dir="x86_64-apple-macosx"
 fi
 
 pushd "gensite" >/dev/null