Add explicit support for ESLint 6.0.0 (#15974)

Preemptively update tests wrt 'parser' requiring an absolute
path rather than a package name, even though the project is
still using ESLint 4.

Fixes #15971

packages/eslint-plugin-react-hooks/__tests__/ESLintRuleExhaustiveDeps-test.js

@@ -12,7 +12,7 @@ const ReactHooksESLintPlugin = require('eslint-plugin-react-hooks');
 const ReactHooksESLintRule = ReactHooksESLintPlugin.rules['exhaustive-deps'];
 
 ESLintTester.setDefaultConfig({
-  parser: 'babel-eslint',
+  parser: require.resolve('babel-eslint'),
   parserOptions: {
     ecmaVersion: 6,
     sourceType: 'module',

packages/eslint-plugin-react-hooks/__tests__/ESLintRulesOfHooks-test.js

@@ -12,7 +12,7 @@ const ReactHooksESLintPlugin = require('eslint-plugin-react-hooks');
 const ReactHooksESLintRule = ReactHooksESLintPlugin.rules['rules-of-hooks'];
 
 ESLintTester.setDefaultConfig({
-  parser: 'babel-eslint',
+  parser: require.resolve('babel-eslint'),
   parserOptions: {
     ecmaVersion: 6,
     sourceType: 'module',

packages/eslint-plugin-react-hooks/package.json

@@ -29,6 +29,6 @@
   },
   "homepage": "https://reactjs.org/",
   "peerDependencies": {
-    "eslint": "^3.0.0 || ^4.0.0 || ^5.0.0"
+    "eslint": "^3.0.0 || ^4.0.0 || ^5.0.0 || ^6.0.0"
   }
 }