chore: pick testnet activation heights for epoch 3.1 and stacks halvenings

Author: jcnelson

stacks-common/src/types/mod.rs

@@ -172,19 +172,19 @@ pub const COINBASE_INTERVALS_TESTNET: LazyCell<[CoinbaseInterval; 5]> = LazyCell
         },
         CoinbaseInterval {
             coinbase: 500 * u128::from(MICROSTACKS_PER_STACKS),
-            effective_start_height: 1000,
+            effective_start_height: 77_777,
         },
         CoinbaseInterval {
             coinbase: 250 * u128::from(MICROSTACKS_PER_STACKS),
-            effective_start_height: 2000,
+            effective_start_height: 77_777 * 7,
         },
         CoinbaseInterval {
             coinbase: 125 * u128::from(MICROSTACKS_PER_STACKS),
-            effective_start_height: 3000,
+            effective_start_height: 77_777 * 14,
         },
         CoinbaseInterval {
             coinbase: (625 * u128::from(MICROSTACKS_PER_STACKS)) / 10,
-            effective_start_height: 4000,
+            effective_start_height: 77_777 * 21,
         },
     ];
     assert!(CoinbaseInterval::check_order(&emissions_schedule));

testnet/stacks-node/conf/testnet-follower-conf.toml

@@ -78,3 +78,7 @@ start_height = 6
 [[burnchain.epochs]]
 epoch_name = "3.0"
 start_height = 56_457
+
+[[burnchain.epochs]]
+epoch_name = "3.1"
+start_height = 77_770