Push Docker using Linux build

Instead of doing a separate redundant build. The main problem was that
the files weren't being cached. There is probably a better way of
solving this but this seems to be the simplest for now.

.travis.yml

@@ -18,7 +18,7 @@ jobs:
     - name: "Linux build"
       os: linux
       dist: trusty
-      env: TARGET="linux"
+      env: TARGET="linux" PUSH_DOCKER="true"
       if: tag IS blank
       script: scripts/ci.bash
     - name: "Alpine build"
@@ -31,12 +31,6 @@ jobs:
       os: osx
       if: tag IS blank
       script: travis_wait 40 scripts/ci.bash
-    - name: "Docker build"
-      os: linux
-      dist: trusty
-      env: DOCKER_BUILD="true"
-      if: branch == master AND tag IS blank
-      script: docker build --build-arg githubToken="$GITHUB_TOKEN" --build-arg codeServerVersion="$VERSION" --build-arg vscodeVersion="$VSCODE_VERSION" -t codercom/code-server:"$TAG" -t codercom/code-server:v2 .
 
 git:
   depth: 3
@@ -46,7 +40,7 @@ before_deploy:
   - git config --local user.name "$USER_NAME"
   - git config --local user.email "$USER_EMAIL"
   - if ! git tag "$TAG" "$TRAVIS_COMMIT" ; then echo "$TAG already exists"; fi
-  - if [[ -n "$DOCKER_BUILD" ]] ; then echo "$DOCKER_PASSWORD" | docker login -u "$DOCKER_USERNAME" --password-stdin ; fi
+  - if [[ -n "$PUSH_DOCKER" ]] ; then echo "$DOCKER_PASSWORD" | docker login -u "$DOCKER_USERNAME" --password-stdin ; fi
 
 deploy:
   - provider: releases
@@ -67,11 +61,11 @@ deploy:
 
   - provider: script
     skip_cleanup: true
-    script: docker push codercom/code-server:"$TAG" ; docker push codercom/code-server:v2
+    script: docker build -f ./scripts/ci.dockerfile --build-arg -t codercom/code-server:"$TAG" -t codercom/code-server:v2 . && docker push codercom/code-server:"$TAG" && docker push codercom/code-server:v2
     on:
       repo: cdr/code-server
       branch: master
-      condition: -n "$DOCKER_BUILD"
+      condition: -n "$PUSH_DOCKER"
 
 cache:
   yarn: true