fix: symbolRegex in isStrongPassword to include '\' (#2278)

* Modified symbolRegex in isStrongPassword to include '\'

* Modify test to check validity of strong password with \ character

Author: nandavikas

src/lib/isStrongPassword.js

@@ -4,7 +4,7 @@ import assertString from './util/assertString';
 const upperCaseRegex = /^[A-Z]$/;
 const lowerCaseRegex = /^[a-z]$/;
 const numberRegex = /^[0-9]$/;
-const symbolRegex = /^[-#!$@£%^&*()_+|~=`{}\[\]:";'<>?,.\/ ]$/;
+const symbolRegex = /^[-#!$@£%^&*()_+|~=`{}\[\]:";'<>?,.\/\\ ]$/;
 
 const defaultOptions = {
   minLength: 8,

test/validators.test.js

@@ -13020,6 +13020,7 @@ describe('Validators', () => {
         '+&DxJ=X7-4L8jRCD',
         'etV*p%Nr6w&H%FeF',
         '£3.ndSau_7',
+        'VaLIDWith\\Symb0l',
       ],
       invalid: [
         '',