feat(rules): add 'no-jest-import' rule to the recommended config (#99)

Fixes #98

Author: ranyitz

README.md

@@ -86,6 +86,7 @@ for more information about extending configuration files.
 | [no-focused-tests](docs/rules/no-focused-tests.md)                 | Disallow focused tests                                            | ![recommended](https://img.shields.io/badge/-recommended-lightgrey.svg) |                                                             |
 | [no-hooks](docs/rules/no-hooks.md)                                 | Disallow setup and teardown hooks                                 |                                                                         |                                                             |
 | [no-identical-title](docs/rules/no-identical-title.md)             | Disallow identical titles                                         | ![recommended](https://img.shields.io/badge/-recommended-lightgrey.svg) |                                                             |
+| [no-jest-import](docs/rules/no-jest-import.md)                     | Disallow importing `jest`                                         | ![recommended](https://img.shields.io/badge/-recommended-lightgrey.svg) |                                                             |
 | [no-large-snapshots](docs/rules/no-large-snapshots.md)             | Disallow large snapshots                                          |                                                                         |                                                             |
 | [no-test-prefixes](docs/rules/no-test-prefixes.md)                 | Disallow using `f` & `x` prefixes to define focused/skipped tests |                                                                         | ![fixable](https://img.shields.io/badge/-fixable-green.svg) |
 | [prefer-to-have-length](docs/rules/prefer-to-have-length.md)       | Suggest using `toHaveLength()`                                    | ![recommended](https://img.shields.io/badge/-recommended-lightgrey.svg) | ![fixable](https://img.shields.io/badge/-fixable-green.svg) |

index.js

@@ -30,6 +30,7 @@ module.exports = {
         'jest/no-disabled-tests': 'warn',
         'jest/no-focused-tests': 'error',
         'jest/no-identical-title': 'error',
+        'jest/no-jest-import': 'warn',
         'jest/prefer-to-have-length': 'warn',
         'jest/valid-expect': 'error',
       },