Improve CI caching (#416)

* Adjust linux distro to ubuntu 14.04

* Cache lib directory for speedy builds

* Fix path linking for default extensions

* Update reset

* Reset to head

* Improve caching

* Still run yarn in CI

* Update yarn before install

* Increase cache timeout

* Install vscode from vstar

* Undo data-dir changes to CLI, add back clean, remove unused CI func

* Remove additional flags added

* Remove unused dependency

* Reset vscode install dir so patching always works

.travis.yml

@@ -6,11 +6,12 @@ env:
 matrix:
   include:
   - os: linux
-    dist: ubuntu
+    dist: trusty
   - os: osx
 before_install:
 - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then sudo apt-get install libxkbfile-dev
   libsecret-1-dev; fi
+- npm install -g yarn@1.12.3
 script:
 - scripts/build.sh
 before_deploy:
@@ -35,4 +36,8 @@ deploy:
   on:
     repo: codercom/code-server
     branch: master
-cache: yarn
+cache:
+  yarn: true
+  timeout: 1000
+  directories:
+  - .cache