Travis: update Lua/luajit; build in /tmp (#1985)

Building in /tmp avoids files to be looked at / searched for e.g. with
luacov.

.travis.yml

@@ -45,24 +45,31 @@ install:
 
   # Need xorg-macros
   - sudo apt-get install -y xutils-dev
-  - git clone --recursive https://github.com/Airblader/xcb-util-xrm.git && cd xcb-util-xrm && ./autogen.sh --prefix=/usr && make && sudo make install && cd -
+  - |
+    set -e
+    (git clone --depth 1 --recursive https://github.com/Airblader/xcb-util-xrm.git /tmp/xcb-util-xrm
+     cd /tmp/xcb-util-xrm
+     ./autogen.sh --prefix=/usr
+     make && sudo make install)
 
   # Install Lua (per env).
   # Note that Lua 5.3 is installed manually, because it is not available in Ubuntu Trusty.
   - |
     set -e
     if [[ "$LUA" == "5.3" ]]; then
-      wget http://www.lua.org/ftp/lua-5.3.3.tar.gz -O lua.tar.gz
-      tar -xvzf lua.tar.gz
       (echo '#!/bin/sh' ; echo 'set -x' ; echo 'gcc -shared -Wl,--no-undefined -o "$@" -ldl -lm') > /tmp/myar
       chmod a+x /tmp/myar
-      (cd lua-5.3.3/src \
+      (cd /tmp
+       wget http://www.lua.org/ftp/lua-5.3.4.tar.gz -O lua.tar.gz
+       tar -xvzf lua.tar.gz
+       cd lua-5.3.*/src \
         && make SYSCFLAGS="-DLUA_USE_LINUX -ULUA_COMPAT_5_2 -DLUA_USE_APICHECK" SYSLIBS="-Wl,-E -ldl -lreadline" LUA_A=liblua.so MYCFLAGS="-fPIC" RANLIB=: AR="/tmp/myar" liblua.so \
         && cd .. \
         && sudo make INSTALL_TOP=/usr/ INSTALL_INC=${LUAINCLUDE} TO_LIB=liblua.so linux install)
     elif [[ "$LUANAME" == "luajit-2.0" ]]; then
-      git clone http://luajit.org/git/luajit-2.0.git
-      (cd luajit-2.0 && sudo make install PREFIX=/usr)
+      (wget http://luajit.org/download/LuaJIT-2.0.5.tar.gz -O- | tar xzf - -C /tmp
+       cd /tmp/LuaJIT-*
+       sudo make install PREFIX=/usr)
 
       # "Create" /usr/bin/lua if needed (Yup, this is a bad hack)
       if [ ! -e "/usr/bin/lua" ]; then sudo ln -s /usr/bin/luajit /usr/bin/lua; fi