Add sshfs command

packages/sshfs.rb

+require 'package'
+
+class Sshfs < Package
+  version '2.8'
+  source_url 'https://github.com/libfuse/sshfs/releases/download/sshfs_2.8/sshfs-2.8.tar.gz'
+  source_sha1 '2b792aa5b3a45e0c3fe65c44bd9da8f64a690830'
+
+  depends_on 'glib2'
+  depends_on 'fuse'
+
+  def self.build
+    system "./configure --prefix=/usr/local"
+    system "make"
+  end
+
+  def self.install
+    system "make", "DESTDIR=#{CREW_DEST_DIR}", "install"
+  end
+end