MAPG-242 add captcha validation for signup

views/login/signup.php

@@ -1,3 +1,4 @@
+@js(https://www.google.com/recaptcha/api.js)
 @js(js/login/signup.js)
 
 @extends(templates/layout_normal)
@@ -15,6 +16,11 @@
                 <input type="password" class="text big fullWidth marginTop" name="password" placeholder="Password" required minlength="6">
                 <input type="password" class="text big fullWidth marginTop" name="password_confirm" placeholder="Password confirmation" minlength="6">
             <?php endif; ?>
+            <?php if (!empty($_ENV['RECAPTCHA_SITEKEY'])): ?>
+                <div class="marginTop">
+                    <div class="g-recaptcha" data-sitekey="<?= $_ENV['RECAPTCHA_SITEKEY'] ?>"></div>
+                </div>
+            <?php endif; ?>
             <p id="signupFormError" class="formError justify marginTop"></p>
             <div class="right">
                 <button class="marginTop" type="submit">Sign up</button><!--