add epoch_schedule sysvar (#6256)

* add epoch_schedule sysvar

* book sheesh!

sdk/src/lib.rs

@@ -2,6 +2,7 @@ pub mod account;
 pub mod account_utils;
 pub mod bpf_loader;
 pub mod clock;
+pub mod epoch_schedule;
 pub mod fee_calculator;
 pub mod hash;
 pub mod inflation;
@@ -17,6 +18,7 @@ pub mod pubkey;
 pub mod rent_calculator;
 pub mod rpc_port;
 pub mod short_vec;
+pub mod slot_hashes;
 pub mod system_instruction;
 pub mod system_program;
 pub mod sysvar;