Don't run on Node.js versions less than 8.10.0 (#1496)

ESLint uses the `s` (dotAll) flag for regular expressions which isn't
supported in Node.js versions earlier than 8.10.0.

.travis.yml

@@ -1,5 +1,6 @@
 language: node_js
 node_js:
+  - 8.10.0
   - 8
   - 10
   - 12

bin/cmd.js

@@ -4,8 +4,8 @@ var match = process.version.match(/v(\d+)\.(\d+)/)
 var major = parseInt(match[1], 10)
 var minor = parseInt(match[2], 10)
 
-if (major >= 9 || (major === 8 && minor >= 6)) {
+if (major >= 9 || (major === 8 && minor >= 10)) {
   require('standard-engine').cli(require('../options'))
 } else {
-  console.error('standard: Node 8 or greater is required. `standard` did not run.')
+  console.error('standard: Node 8.10.0 or greater is required. `standard` did not run.')
 }

package.json

@@ -34,7 +34,7 @@
     "tape": "^4.6.0"
   },
   "engines": {
-    "node": ">=8"
+    "node": ">=8.10.0"
   },
   "homepage": "https://standardjs.com",
   "keywords": [