fix(rules): don't crash on require() (#115)

fixes #114

Author: jacekkopecky

Diff for: rules/__tests__/no-jest-import.test.js

@@ -12,6 +12,7 @@ ruleTester.run('no-jest-import', rule, {
       parserOptions: { sourceType: 'module' },
     },
     'require("somethingElse")',
+    'require()',
     'entirelyDifferent(fn)',
   ],
   invalid: [

Diff for: rules/no-jest-import.js

@@ -22,7 +22,11 @@ module.exports = {
       },
       CallExpression(node) {
         const calleeName = getNodeName(node.callee);
-        if (calleeName === 'require' && node.arguments[0].value === 'jest') {
+        if (
+          calleeName === 'require' &&
+          node.arguments[0] &&
+          node.arguments[0].value === 'jest'
+        ) {
           context.report({
             loc: {
               end: {