[chore] try to fix coverage on PRs.

.travis.yml

@@ -1,10 +1,11 @@
 language: node_js
 node_js:
   - "7"
-  - "6"
 cache: yarn
 before_script:
   - export DISPLAY=:99.0
   - sh -e /etc/init.d/xvfb start
 script:
-    - make tests-ci
+  - COVERAGE=true make tests-single-run
+after_success:
+  - make coveralls

package.json

@@ -29,7 +29,7 @@
     "babel-preset-es2015": "^6.24.1",
     "babel-preset-react": "^6.24.1",
     "babel-preset-stage-2": "^6.24.1",
-    "codeclimate-test-reporter": "^0.4.0",
+    "codeclimate-test-reporter": "^0.5.0",
     "coveralls": "^2.13.1",
     "cross-env": "^5.0.1",
     "envify": "^3.4.1",
@@ -40,7 +40,7 @@
     "eslint-plugin-react": "^7.1.0",
     "expect": "^1.20.2",
     "gitbook-cli": "^2.3.0",
-    "istanbul-instrumenter-loader": "0.2.0",
+    "istanbul-instrumenter-loader": "^2.0.0",
     "karma": "^1.3.0",
     "karma-chrome-launcher": "2.0.0",
     "karma-cli": "1.0.1",
@@ -50,7 +50,7 @@
     "karma-mocha-reporter": "^2.2.1",
     "karma-sourcemap-loader": "^0.3.7",
     "karma-webpack": "^1.8.1",
-    "mocha": "3.2.0",
+    "mocha": "^3.4.2",
     "npm-run-all": "^3.1.2",
     "react": "^15.6.1",
     "react-dom": "^15.6.1",