Update espresso-sequencer-go with new LC ABI (#230)

* Update espresso-sequencer-go with new LC ABI

Instead of using the block height from the first snapshot after the
height in the justification it uses the latest height in the LC
contract. Currently not 100% convinced about correctness but also
believe it should work because any newer tree still contains the header
of interest.

* Undo LC ABI changes

We're not comfortable with the previous change because making a proof
w.r.t to the newest finalized state may cause issues if the batch poster
is lagging behind. This is currently not easy to test so we decided to
revert back to the old flow.

* Use tag of espresso-sequencer-go

go.mod

@@ -7,7 +7,7 @@ replace github.com/VictoriaMetrics/fastcache => ./fastcache
 replace github.com/ethereum/go-ethereum => ./go-ethereum
 
 require (
-	github.com/EspressoSystems/espresso-sequencer-go v0.0.23
+	github.com/EspressoSystems/espresso-sequencer-go v0.0.24
 	github.com/Knetic/govaluate v3.0.1-0.20171022003610-9aa49832a739+incompatible
 	github.com/Shopify/toxiproxy v2.1.4+incompatible
 	github.com/alicebob/miniredis/v2 v2.32.1

go.sum

@@ -7,8 +7,8 @@ github.com/CloudyKit/fastprinter v0.0.0-20200109182630-33d98a066a53/go.mod h1:+3
 github.com/CloudyKit/jet/v3 v3.0.0/go.mod h1:HKQPgSJmdK8hdoAbKUUWajkHyHo4RaU5rMdUywE7VMo=
 github.com/DataDog/zstd v1.4.5 h1:EndNeuB0l9syBZhut0wns3gV1hL8zX8LIu6ZiVHWLIQ=
 github.com/DataDog/zstd v1.4.5/go.mod h1:1jcaCB/ufaK+sKp1NBhlGmpz41jOoPQ35bpF36t7BBo=
-github.com/EspressoSystems/espresso-sequencer-go v0.0.23 h1:3fvNU1fvoH6eBZFleaUGl6AVcWhd+H3/paKHnYHKfdM=
-github.com/EspressoSystems/espresso-sequencer-go v0.0.23/go.mod h1:BbU8N23RGl45QXSf/bYc8OQ8TG/vlMaPC1GU1acqKmc=
+github.com/EspressoSystems/espresso-sequencer-go v0.0.24 h1:VjV4dcA46UaIqmqCvwH5zF3IolZ7U7A7teldr2/gj5k=
+github.com/EspressoSystems/espresso-sequencer-go v0.0.24/go.mod h1:BbU8N23RGl45QXSf/bYc8OQ8TG/vlMaPC1GU1acqKmc=
 github.com/Joker/hpp v1.0.0/go.mod h1:8x5n+M1Hp5hC0g8okX3sR3vFQwynaX/UgSOM9MeBKzY=
 github.com/Knetic/govaluate v3.0.1-0.20171022003610-9aa49832a739+incompatible h1:1G1pk05UrOh0NlF1oeaaix1x8XzrfjIDK47TY0Zehcw=
 github.com/Knetic/govaluate v3.0.1-0.20171022003610-9aa49832a739+incompatible/go.mod h1:r7JcOSlj0wfOMncg0iLm8Leh48TZaKVeNIfJntJ2wa0=