feat: add automated docs deployment to Travis CI with gh-pages script

.travis.yml

@@ -1,13 +1,19 @@
 language: c
 os:
- - osx
  - linux
+ - osx
 compiler:
   - gcc
   - clang
 env:
   - WREN_OPTIONS="" CI_ARCHS="ci_32 ci_64"
   - WREN_OPTIONS="-DWREN_NAN_TAGGING=0" CI_ARCHS="ci_64"
+
+jobs:
+  include:
+    - stage: deploy
+      script: bash util/deployGHP.sh
+
 # Travis VMs are 64-bit but we compile both for 32 and 64 bit. To enable the
 # 32-bit builds to work, we need gcc-multilib.
 addons:
@@ -15,5 +21,8 @@ addons:
     packages:
     - gcc-multilib
     - g++-multilib
+    - python3-markdown
+    - ruby-sass
+
 sudo: false # Enable container-based builds.
 script: make WREN_CFLAGS=${WREN_OPTIONS} ${CI_ARCHS}