fix: add timing constants to better set timeouts

web3.js/src/timing.js

@@ -0,0 +1,7 @@
+// @flow
+
+// These constants should match the values in
+// https://github.com/solana-labs/solana/blob/master/sdk/src/timing.rs
+export const NUM_TICKS_PER_SECOND = 10;
+export const DEFAULT_TICKS_PER_SLOT = 80;
+export const DEFAULT_SLOTS_PER_EPOCH = 64;