Vim: fix installation of Lua

Installs symlinks for Vim to pick it up
(vim/vim#4475).

tests: clean lua stamp file

Closes #65.

Author: blueyed

Makefile

@@ -1,4 +1,4 @@
-TAG:=13
+TAG:=14
 
 build:
 	docker build -t testbed/vim:$(TAG) .

example/Makefile

@@ -70,6 +70,7 @@ test:
 	  if [ "$$(<$(WRITABLE_HOME)/lua)" != "lua was here" ]; then \
 	    echo "Failed to get output from Lua for $${vim}." >&2; exit 1; \
 	  fi; \
+	  $(RM) $(WRITABLE_HOME)/lua; \
 	done; \
 	neovim_tag_version=$$(docker run --rm "$(IMAGE)" neovim-v0.2.0 -u NONE --version | grep '^NVIM'); \
 	if [ "$$neovim_tag_version" != 'NVIM v0.2.0' ]; then \

scripts/install_vim.sh

@@ -121,6 +121,9 @@ EOF
       CONFIG_ARGS="$CONFIG_ARGS --enable-luainterp"
       apk_add_build_dep lua5.3-dev
       apk add lua5.3-libs
+      # Install symlinks to make Vim's configure pick it up.
+      (cd /usr/bin && ln -s lua5.3 lua)
+      (cd /usr/lib && ln -s lua5.3/liblua.so liblua5.3.so)
     else
       echo 'NOTE: -lua is automatically used with Neovim 0.2.1+, and not supported before.'
     fi