Use Xcode9.1 on Travis CI

Author: splhack

.travis.yml

@@ -4,7 +4,7 @@ dist: trusty
 os:
   - osx
 
-osx_image: xcode8
+osx_image: xcode9.1
 
 compiler:
   - clang
@@ -20,7 +20,7 @@ env:
     vi_cv_dll_name_python=/System/Library/Frameworks/Python.framework/Versions/2.7/Python
     vi_cv_dll_name_python3=/usr/local/Frameworks/Python.framework/Versions/3.6/Python
     VIMCMD=src/MacVim/build/Release/MacVim.app/Contents/MacOS/Vim
-    "CONFOPT='--with-features=huge --enable-multibyte --enable-terminal --enable-netbeans --with-tlib=ncurses --enable-cscope --enable-perlinterp=dynamic --enable-pythoninterp=dynamic --enable-python3interp=dynamic --enable-rubyinterp=dynamic --enable-luainterp=dynamic --with-lua-prefix=/usr/local --enable-gui=macvim'"
+    "CONFOPT='--with-features=huge --enable-multibyte --enable-terminal --enable-netbeans --with-tlib=ncurses --enable-cscope --enable-perlinterp=dynamic --enable-pythoninterp=dynamic --enable-python3interp=dynamic --enable-rubyinterp=dynamic --with-ruby-command=/usr/bin/ruby --enable-luainterp=dynamic --with-lua-prefix=/usr/local --enable-gui=macvim'"
 
 sudo: false