Increase security of example RSA key generation from 1024 to 2048 bits (#153)

As per current recommendations (ie. refer https://en.wikipedia.org/wiki/RSA_(cryptosystem)#cite_ref-keymanagement_35-0 )

Author: rpocklin

README.md

@@ -147,11 +147,11 @@ The oidc library used generates Json Web Tokens to create the Access Tokens, so
 
 To generate the private key run this command on the terminal:
 
-    openssl genrsa -out cert/oidc_module.pem 1024
+    openssl genrsa -out cert/oidc_module.pem 2048
 
 If you want to provide a passphrase for your private key run this command instead:
 
-    openssl genrsa -passout pass:myPassPhrase -out cert/oidc_module.pem 1024
+    openssl genrsa -passout pass:myPassPhrase -out cert/oidc_module.pem 2048
 
 Now you need to extract the public key from the private key:
 
@@ -318,4 +318,4 @@ Work in Progress:
 
 ## Running Conformance Tests
 
-See [CONFORMANCE_TEST.md](CONFORMANCE_TEST.md)
+See [CONFORMANCE_TEST.md](CONFORMANCE_TEST.md)