Update reference of parity to latest upstream version

Fixes #8

Cargo.toml

@@ -9,7 +9,7 @@ edition = "2018"
 [dependencies]
 base64 = "0.10.1"
 c_vec = "1.3.3"
-ethcore-builtin = { path = "parity-ethereum/ethcore/builtin" }
+ethcore-builtin = { git = "https://github.com/paritytech/parity-ethereum.git", rev = "acf7c48" }
 lazy_static = "1.3.0"
 libc = "0.2.60"
 parity-bytes = "0.1.0"

Makefile

@@ -19,13 +19,10 @@ all: priv/$(nif_lib) compile
 compile:
 	./rebar3 compile
 
-priv/$(nif_lib): src/lib.rs parity-ethereum/
+priv/$(nif_lib): src/lib.rs
 	cargo build --release
 	cp target/release/$(nif_lib_src) $@
 
 clean:
 	rm -f priv/$(nif_lib) target/release/$(nif_lib_src)
 	./rebar3 clean
-
-parity-ethereum/:
-	git clone https://github.com/aeternity/parity-ethereum.git