travis/build.sh: xbps-src takes care of everything now.

Also this file does not contain any bashism, so use /bin/sh.

common/travis/build.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 #
 # build.sh
 
@@ -6,12 +6,6 @@ if [ "$1" != "$2" ]; then
 	arch="-a $2"
 fi
 
-# Make sure `base-chroot` is really up-to-date
-/hostrepo/xbps-src -H "$HOME"/hostdir -E pkg base-chroot || exit 1
-xbps-install --repo="$HOME"/hostdir/binpkgs -yu || exit 1
-# remove autodeps
-xbps-remove -yo || exit 1
-
 PKGS=$(/hostrepo/xbps-src sort-dependencies $(cat /tmp/templates))
 
 NPROCS=1