chore: remove mutation-observer package

Author: bcarroll22

.travis.yml

@@ -5,19 +5,22 @@ node_js:
   - '9'
   - '10'
   - '11'
-cache: npm
+cache:
+  npm: true
+  directories:
+    - coverage
 notifications:
   email: false
 branches:
   only:
     - master
-install: npm install
+install: npm ci
 script: npm run test:coverage
 jobs:
   include:
     - stage: release
       node_js: '10'
       install: npm install -g codecov
-      script: 
+      script:
         - codecov
         - npm run semantic-release

package.json

@@ -33,7 +33,6 @@
   "author": "Brandon Carroll <brandonvcarroll@gmail.com> (https://github.com/bcarroll22)",
   "license": "MIT",
   "dependencies": {
-    "@sheerun/mutationobserver-shim": "^0.3.2",
     "pretty-format": "^24.5.0",
     "react-test-renderer": "^16.8.5",
     "wait-for-expect": "^1.1.1"