Flow: use implicit exact object types

Flow standard is now to use `{ }` for strict objects and `{ key: value, ... }` for open objects, see: facebook/relay@6fa0b0d and facebook/react-native@00cfb0f

This change should be without any problems as longs as users of our NPM libraries are using Flow with `exact_by_default=true` (which is now pretty standard I'd say).

Here is how object types behave before this change:

```
type A = { x: number }; // already "exact" type but disallowed because it would be confusing to mix different syntaxes
type B = { x: number, ... }; // this is inexact
type C = {| x: number |}; // this is explicitly exact and the only allowed way how to describe type "exactness"
```

Here is how object types behave _after_ this change:

```
type A = { x: number }; // this is the only allowed syntax for "exact" type
type B = { x: number, ... }; // this is still inexact
type C = {| x: number |}; // this is also exact but no longer allowed (so it's not confusing)
```

Some related (non-blocking) issues:

- gajus/eslint-plugin-flowtype#467
- facebook/flow#8612

adeira-source-id: 5f0c905ae627f670804581f78c1b570f3f71a1e6

src/sxTailwind.js

@@ -2,7 +2,7 @@
 
 import levenshtein from 'fast-levenshtein';
 
-export function suggestUtility(className: string, styles: {| +[string]: any |}): string {
+export function suggestUtility(className: string, styles: { +[string]: any }): string {
   return Object.keys(styles).sort((first, second) => {
     const firstScore = levenshtein.get(className, first);
     const secondScore = levenshtein.get(className, second);

src/tailwindToSx.js

@@ -14,12 +14,12 @@ import purgeUnusedStyles from 'tailwindcss/lib/lib/purgeUnusedStyles';
 import processPlugins from 'tailwindcss/lib/util/processPlugins';
 import corePlugins from 'tailwindcss/lib/corePlugins';
 
-type SxTailwindDefinitions = {|
-  +keyframes: {| +[string]: any |},
-  +styles: {| +[string]: any |},
-|};
+type SxTailwindDefinitions = {
+  +keyframes: { +[string]: any },
+  +styles: { +[string]: any },
+};
 
-export function generateTailwind(config: {| +[string]: any |}): Promise<SxTailwindDefinitions> {
+export function generateTailwind(config: { +[string]: any }): Promise<SxTailwindDefinitions> {
   return convert(
     ` @tailwind base;
       @tailwind components;
@@ -31,7 +31,7 @@ export function generateTailwind(config: {| +[string]: any |}): Promise<SxTailwi
 
 export default async function convert(
   css: string,
-  tailwindConfig: {| +[string]: any |},
+  tailwindConfig: { +[string]: any },
 ): Promise<SxTailwindDefinitions> {
   const processor = getTailwindProcessor(tailwindConfig);
   const postCss = await processor.process(css, { from: '' });