Remove phone number validation

Remove check for mobile number using regex since paynow validates mobile numbers as outlined in issue #7 brought up by @tzifudzi

src/main/java/webdev/payments/Paynow.java

@@ -223,11 +223,7 @@ public final InitResponse sendMobile(Payment payment, String phone, String metho
         if (payment.getTotal().compareTo(BigDecimal.ZERO) <= 0) {
             throw new EmptyCartException();
         }
-
-        if (!phone.matches("07([7,8])((\\1=7)[1-9]|[2-5])\\d{6}")) {
-            throw new IllegalArgumentException("Invalid phone number");
-        }
-
+
         return initMobile(payment, phone, method);
     }
 
@@ -332,4 +328,4 @@ private HashMap<String, String> formatMobileInitRequest(Payment payment, String
 
         return items;
     }
-}
+}