Improve TravisCI configuration (#3847)

* Improve '.travis.yml' configuration.

* Add 'cleanup: false' to TravisCI deployments.

* Add 'git.depth: 1' to 'Git tag' job.

* Reorder 'git' key in TravisCI config

.travis.yml

@@ -1,5 +1,4 @@
 os: linux
-language: node_js
 
 jobs:
   include:
@@ -7,6 +6,8 @@ jobs:
       name: "Lint"
       language: node_js
       node_js: 10
+      git:
+        depth: 1
       script:
         - npm run jsonlint
         - npm run svglint
@@ -14,7 +15,12 @@ jobs:
         - npm run our-lint
     - name: "Build website"
       language: ruby
-      rvm: 2.4.1
+      rvm: 2.5.3
+      git:
+        depth: 1
+      cache:
+        directories:
+          - /home/travis/.rvm/
       install:
         - gem install jekyll
       script:
@@ -22,12 +28,16 @@ jobs:
     - name: "Test package"
       language: node_js
       node_js: 10
+      git:
+        depth: 1
       script:
         - npm run test
 
-    - stage: deploy
+    - stage: "Deploy"
       name: "Git tag"
       language: shell
+      git:
+        depth: 1
       if: branch = master
 
       before_deploy:
@@ -38,9 +48,12 @@ jobs:
       deploy:
         provider: releases
         token: "$GITHUB_TOKEN"
+        cleanup: false
     - name: "NPM Package"
       language: node_js
       node_js: 10
+      git:
+        depth: 1
       if: branch = master
 
       deploy:
@@ -48,6 +61,7 @@ jobs:
         provider: npm
         email: "$NPM_EMAIL"
         api_token: "$NPM_KEY"
+        cleanup: false
         on:
           branch: master