chore: update dependencies

Author: dignifiedquire

.travis.yml

@@ -3,23 +3,19 @@ language: node_js
 
 matrix:
   include:
-  - node_js: 4
+  - node_js: 8
     env: CXX=g++-4.8
-  - node_js: 6
+  - node_js: 10
     env:
       - SAUCE=true
       - CXX=g++-4.8
   - node_js: stable
     env: CXX=g++-4.8
 
-# Make sure we have new NPM.
-before_install:
-  - npm install -g npm
-
 script:
-  - npm run lint
-  - npm run test
-  - npm run coverage
+  - yarn lint
+  - yarn test
+  - yran coverage
 
 before_script:
   - export DISPLAY=:99.0

package.json

@@ -49,7 +49,7 @@
   "license": "MIT",
   "readmeFilename": "README.md",
   "dependencies": {
-    "bignumber.js": "^6.0.0",
+    "bignumber.js": "^7.2.1",
     "commander": "^2.15.0",
     "ieee754": "^1.1.8",
     "json-text-sequence": "^0.1"