Upgrade rust/crates/futures-channel to 0.3.12

Test: make
Change-Id: I2cd8faf5d73c915d9dfc92c1bf7232e31010c05c
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
index 76aef73..5b4c639 100644
--- a/Cargo.toml.orig
+++ b/Cargo.toml.orig
@@ -1,12 +1,12 @@
 [package]
 name = "futures-channel"
 edition = "2018"
-version = "0.3.7"
+version = "0.3.12"
 authors = ["Alex Crichton <alex@alexcrichton.com>"]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-lang/futures-rs"
 homepage = "https://rust-lang.github.io/futures-rs"
-documentation = "https://docs.rs/futures-channel/0.3.7"
+documentation = "https://docs.rs/futures-channel/0.3"
 description = """
 Channels for asynchronous communication using futures-rs.
 """
@@ -24,8 +24,12 @@
 cfg-target-has-atomic = ["futures-core/cfg-target-has-atomic"]
 
 [dependencies]
-futures-core = { path = "../futures-core", version = "0.3.7", default-features = false }
-futures-sink = { path = "../futures-sink", version = "0.3.7", default-features = false, optional = true }
+futures-core = { path = "../futures-core", version = "0.3.12", default-features = false }
+futures-sink = { path = "../futures-sink", version = "0.3.12", default-features = false, optional = true }
+
+[dev-dependencies]
+futures = { path = "../futures", default-features = true }
+futures-test = { path = "../futures-test", default-features = true }
 
 [package.metadata.docs.rs]
 all-features = true