[NC-1374] Use default java secureRandom (#34)

Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

build.gradle

@@ -305,8 +305,7 @@ applicationDefaultJvmArgs = [
   "-Dpantheon.home=PANTHEON_HOME",
   // We shutdown log4j ourselves, as otherwise his shutdown hook runs before our own and whatever
   // happens during shutdown is not logged.
-  "-Dlog4j.shutdownHookEnabled=false",
-  "-Djava.security.egd=file:/dev/urandom"
+  "-Dlog4j.shutdownHookEnabled=false"
 ]
 
 run {

crypto/src/main/java/net/consensys/pantheon/crypto/SecureRandomProvider.java

@@ -3,7 +3,7 @@ package net.consensys.pantheon.crypto;
 import java.security.SecureRandom;
 
 public class SecureRandomProvider {
-  private static final SecureRandom publicSecureRandom = new PRNGSecureRandom();
+  private static final SecureRandom publicSecureRandom = secureRandom();
 
   // Returns a shared instance of secure random intended to be used where the value is used publicly
   public static SecureRandom publicSecureRandom() {
@@ -11,6 +11,11 @@ public class SecureRandomProvider {
   }
 
   public static SecureRandom createSecureRandom() {
-    return new PRNGSecureRandom();
+    return secureRandom();
+  }
+
+  @SuppressWarnings("DoNotCreateSecureRandomDirectly")
+  private static SecureRandom secureRandom() {
+    return new SecureRandom();
   }
 }