chore: upgrade to jest 26 + drop node 8 support (#205)

BREAKING CHANGE: drop node 8 support

Author: AndrewLeedham

.travis.yml

@@ -1,6 +1,5 @@
 language: node_js
 node_js:
-  - 8
   - 10
   - 12
 before_install:
@@ -20,4 +19,4 @@ jobs:
         provider: script
         skip_cleanup: true
         script:
-          - npx semantic-release
+          - npx semantic-release