src: Removing unnecessary use of cref() in concert with make_shared

This commit also replaces all usages of shared_ptr<T>(new T) with
make_shared<T> in Face class implementation.

Change-Id: I44971c44eb7f2c25ecfe00e185309973c9cbd246
Refs: #1592
diff --git a/src/security/validator-regex.cpp b/src/security/validator-regex.cpp
index b4fd1b8..4c74e79 100644
--- a/src/security/validator-regex.cpp
+++ b/src/security/validator-regex.cpp
@@ -46,7 +46,7 @@
                                        const OnDataValidationFailed& onValidationFailed)
 {
   shared_ptr<IdentityCertificate> certificate =
-    make_shared<IdentityCertificate>(cref(*signCertificate));
+    make_shared<IdentityCertificate>(*signCertificate);
 
   if (!certificate->isTooLate() && !certificate->isTooEarly())
     {
@@ -137,7 +137,7 @@
 
                   Interest interest(sig.getKeyLocator().getName());
                   shared_ptr<ValidationRequest> nextStep =
-                    make_shared<ValidationRequest>(cref(interest),
+                    make_shared<ValidationRequest>(interest,
                                                    onKeyValidated,
                                                    onKeyValidationFailed,
                                                    3,