feat(prefer-to-be-null): remove rule

BREAKING CHANGE: removed `prefer-to-be-null` rule

Author: G-Rath

docs/rules/prefer-to-be-null.md

@@ -91,7 +91,6 @@ Object {
     "rules": Object {
       "jest/no-alias-methods": "warn",
       "jest/prefer-to-be": "error",
-      "jest/prefer-to-be-null": "error",
       "jest/prefer-to-be-undefined": "error",
       "jest/prefer-to-contain": "error",
       "jest/prefer-to-have-length": "error",

src/__tests__/__snapshots__/rules.test.ts.snap

@@ -2,7 +2,7 @@ import { existsSync } from 'fs';
 import { resolve } from 'path';
 import plugin from '../';
 
-const numberOfRules = 45;
+const numberOfRules = 44;
 const ruleNames = Object.keys(plugin.rules);
 const deprecatedRules = Object.entries(plugin.rules)
   .filter(([, rule]) => rule.meta.deprecated)

src/__tests__/rules.test.ts

@@ -74,7 +74,6 @@ export = {
       rules: {
         'jest/no-alias-methods': 'warn',
         'jest/prefer-to-be': 'error',
-        'jest/prefer-to-be-null': 'error',
         'jest/prefer-to-be-undefined': 'error',
         'jest/prefer-to-contain': 'error',
         'jest/prefer-to-have-length': 'error',