chore/ci: bring ci to the theme development

.travis.yml

@@ -0,0 +1,25 @@
+language: node_js
+node_js:
+  - "10"
+git:
+  depth: 2
+  quiet: true
+install:
+  - npm install hexo-cli -g
+before_script:
+  - git clone https://github.com/theme-suka/hexo-theme-unit-test.git suka-theme-test --depth=5
+  - cd suka-theme-test
+  - rm -rf .git
+  - npm i
+  - chmod +x ./install-theme.sh
+  - ./install-theme.sh
+script:
+  - \cp -f ./theme_config.yml themes/suka/_config.yml
+  - hexo clean
+  - hexo g
+  - chmod +x ./deploy.sh
+  - ./deploy.sh > /dev/null
+cache:
+  directories:
+    - node_modules
+    - themes/suka/node_modules