SYNOPSIS
Retrieves the current EC2 instance's IAM credentials and caches them until they expire.
use VM::EC2::Security::CredentialCache;
# return a VM::EC2::Security::Credentials if available undef otherwise.
my $credentials = VM::EC2::Security::CredentialCache->get();
DESCRIPTION
This module provides a cache for an EC2's IAM credentials represented by VM::EC2::Security::Credentials. Rather than retriving the credentials for every possible call that uses them, cache them until they expire and retrieve them again if they have expired.