update the AMT implementation

This change ensures the bitmap is reset on flush.

go.mod

@@ -23,6 +23,7 @@ require (
 	github.com/fatih/color v1.8.0
 	github.com/filecoin-project/filecoin-ffi v0.30.4-0.20200716204036-cddc56607e1d
 	github.com/filecoin-project/go-address v0.0.4
+	github.com/filecoin-project/go-amt-ipld/v2 v2.1.1-0.20201006184820-924ee87a1349 // indirect
 	github.com/filecoin-project/go-bitfield v0.2.1
 	github.com/filecoin-project/go-cbor-util v0.0.0-20191219014500-08c40a1e63a2
 	github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03

go.sum

@@ -228,6 +228,8 @@ github.com/filecoin-project/go-address v0.0.4 h1:gSNMv0qWwH16fGQs7ycOUrDjY6YCSsg
 github.com/filecoin-project/go-address v0.0.4/go.mod h1:jr8JxKsYx+lQlQZmF5i2U0Z+cGQ59wMIps/8YW/lDj8=
 github.com/filecoin-project/go-amt-ipld/v2 v2.1.0 h1:t6qDiuGYYngDqaLc2ZUvdtAg4UNxPeOYaXhBWSNsVaM=
 github.com/filecoin-project/go-amt-ipld/v2 v2.1.0/go.mod h1:nfFPoGyX0CU9SkXX8EoCcSuHN1XcbN0c6KBh7yvP5fs=
+github.com/filecoin-project/go-amt-ipld/v2 v2.1.1-0.20201006184820-924ee87a1349 h1:pIuR0dnMD0i+as8wNnjjHyQrnhP5O5bmba/lmgQeRgU=
+github.com/filecoin-project/go-amt-ipld/v2 v2.1.1-0.20201006184820-924ee87a1349/go.mod h1:vgmwKBkx+ca5OIeEvstiQgzAZnb7R6QaqE1oEDSqa6g=
 github.com/filecoin-project/go-bitfield v0.2.0 h1:gCtLcjskIPtdg4NfN7gQZSQF9yrBQ7mkT0qCJxzGI2Q=
 github.com/filecoin-project/go-bitfield v0.2.0/go.mod h1:CNl9WG8hgR5mttCnUErjcQjGvuiZjRqK9rHVBsQF4oM=
 github.com/filecoin-project/go-bitfield v0.2.1 h1:S6Uuqcspqu81sWJ0He4OAfFLm1tSwPdVjtKTkl5m/xQ=
@@ -1401,6 +1403,7 @@ github.com/whyrusleeping/cbor-gen v0.0.0-20200504204219-64967432584d/go.mod h1:W
 github.com/whyrusleeping/cbor-gen v0.0.0-20200710004633-5379fc63235d/go.mod h1:fgkXqYy7bV2cFeIEOkVTZS/WjXARfBqSH6Q2qHL33hQ=
 github.com/whyrusleeping/cbor-gen v0.0.0-20200715143311-227fab5a2377/go.mod h1:fgkXqYy7bV2cFeIEOkVTZS/WjXARfBqSH6Q2qHL33hQ=
 github.com/whyrusleeping/cbor-gen v0.0.0-20200806213330-63aa96ca5488/go.mod h1:fgkXqYy7bV2cFeIEOkVTZS/WjXARfBqSH6Q2qHL33hQ=
+github.com/whyrusleeping/cbor-gen v0.0.0-20200723185710-6a3894a6352b/go.mod h1:fgkXqYy7bV2cFeIEOkVTZS/WjXARfBqSH6Q2qHL33hQ=
 github.com/whyrusleeping/cbor-gen v0.0.0-20200810223238-211df3b9e24c/go.mod h1:fgkXqYy7bV2cFeIEOkVTZS/WjXARfBqSH6Q2qHL33hQ=
 github.com/whyrusleeping/cbor-gen v0.0.0-20200812213548-958ddffe352c/go.mod h1:fgkXqYy7bV2cFeIEOkVTZS/WjXARfBqSH6Q2qHL33hQ=
 github.com/whyrusleeping/cbor-gen v0.0.0-20200826160007-0b9f6c5fb163 h1:TtcUeY2XZSriVWR1pXyfCBWIf/NGC2iUdNw1lofUjUU=