chore: add Travis CI docs deployment job and update build dependencies

- Add automatic docs deployment stage for master branch pushes in .travis.yml
- Include python3-markdown, python3-pygments, python3-setuptools, and ruby-sass as build dependencies
- Switch from container-based to sudo-required builds with trusty dist for custom Pygments lexer installation
- Ensure build directory exists before generating docs in Makefile

util/deploy_docs_from_travis.sh

@@ -0,0 +1,33 @@
+#!/bin/bash
+set -e
+
+# Install the Wren Pygments lexer.
+cd util/pygments-lexer
+sudo python3 setup.py develop
+cd ../..
+
+# Build the docs.
+make gh-pages
+
+# Clone the repo at the gh-pages branch.
+git clone https://${GH_TOKEN}@github.com/${TRAVIS_REPO_SLUG} gh-pages-repo \
+    --branch gh-pages --depth 1
+cd gh-pages-repo
+
+# Copy them into the gh-pages branch.
+rm -rf *
+cp -r ../build/gh-pages/* .
+
+# Restore CNAME file that gets deleted by `rm -rf *`.
+echo "wren.io" > "CNAME"
+
+git status
+ls
+
+if ! $( git diff-index --quiet HEAD ) ; then
+  git config user.name "Travis CI"
+  git config user.email "$COMMIT_AUTHOR_EMAIL"
+  git add --all .
+  git commit -m "Deploy to GitHub Pages: ${SHA}"
+  git push
+fi

util/pygments-lexer/Wren.egg-info/PKG-INFO

@@ -8,5 +8,6 @@ Home-page: UNKNOWN
 Author: Robert Nystrom
 Author-email: UNKNOWN
 License: UNKNOWN
+Description-Content-Type: UNKNOWN
 Description: UNKNOWN
 Platform: UNKNOWN

util/wren.mk

@@ -110,7 +110,7 @@ endif
 ifneq (,$(findstring darwin,$(OS)))
 	SHARED_EXT := dylib
 else
-	SHARED_LIB_FLAGS := -Wl,-soname,$@.so
+	SHARED_LIB_FLAGS := -Wl,-soname,libwren.so
 	SHARED_EXT := so
 
 	# Link in the right libraries needed by libuv on Windows and Linux.

util/xcode/wren.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>