Refactor Tooltip into a function component (#355)

## This change includes:

- Refactoring Tooltip to be a function component, using hooks for state and effects
- Remove the intermediary EscapableTooltip (Fixes #354)
- Update all the unit tests to avoid using `setState()` and `state()` in favour of simulating clicks and asserting the DOM directly. This is compatible with hooks, and is a better design of black-box testing
- Split out server tests and run them in Jest's server environment
- Upgrade Enzyme (only a minor version bump) to support new Hooks testing features (see enzymejs/enzyme#2073)

.eslintrc.js

@@ -38,7 +38,7 @@ module.exports = {
             // Since this code must run in IE11, it has stricter constraints than other parts of
             // this repo.
             files: ['packages/thumbprint-react/**/*'],
-            excludedFiles: ['test.jsx', '*.config.js'],
+            excludedFiles: ['*test.jsx', '*.config.js'],
             rules: {
                 // Check for uses of browser/DOM APIs that are not available in our supported browsers.
                 'compat/compat': 'error',

package.json

@@ -28,8 +28,8 @@
         "babel-jest": "^24.0.0",
         "babel-plugin-dynamic-import-node": "^2.2.0",
         "babel-plugin-external-helpers": "^6.22.0",
-        "enzyme": "^3.9.0",
-        "enzyme-adapter-react-16": "^1.12.1",
+        "enzyme": "^3.10.0",
+        "enzyme-adapter-react-16": "^1.14.0",
         "enzyme-to-json": "^3.3.4",
         "eslint": "^5.9.0",
         "eslint-config-airbnb": "^17.1.0",

packages/thumbprint-react/CHANGELOG.md

@@ -13,6 +13,7 @@
 -   [Patch] Refactor ModalCurtain to be a function component and use hooks.
 -   [Patch] Refactor Tooltip to use the new hooks.
 -   [Patch] Refactor Popover to use the new hooks.
+-   [Patch] Refactor Tooltip to be a functional component and update its tests.
 
 ### Fixed