Bump rand to 0.8

The changelog is pretty detailed, but at a first glance I can't notice
any relevant looking changes that might be breaking.
tests are passing.

Signed-off-by: Jonathan Schwender <[email protected]>

Author: jschwe

Cargo.lock

@@ -57,7 +57,7 @@ num_cpus = "1.0"
 number_prefix = "0.4"
 openssl = { version = "0.10", optional = true }
 percent-encoding = { version = "2", optional = true }
-rand = "0.7"
+rand = "0.8.4"
 redis = { version = "0.21", optional = true, default-features = false, features = ["aio", "tokio-comp", "tokio-native-tls-comp"] }
 regex = "1"
 reqwest = { version = "0.11", features = ["json", "blocking"], optional = true }