Refactor reward curve (#3668)

* move test in tests dir

* comment

* refactor

substrate/Cargo.toml

@@ -96,7 +96,6 @@ members = [
 	"srml/session",
 	"srml/staking",
 	"srml/staking/reward-curve",
-	"srml/staking/reward-curve/test",
 	"srml/sudo",
 	"srml/system",
 	"srml/timestamp",

substrate/srml/staking/reward-curve/Cargo.toml

@@ -8,7 +8,6 @@ edition = "2018"
 proc-macro = true
 
 [dependencies]
-# sr-api-macros = { path = "../../../core/sr-api-macros" }
 syn = { version = "1.0", features = [ "full", "visit" ] }
 quote = "1.0"
 proc-macro2 = "1.0"

substrate/srml/staking/reward-curve/src/lib.rs

@@ -279,6 +279,8 @@ fn compute_points(input: &INposInput) -> Vec<(u32, u32)> {
 	let mut delta_y = max_length;
 	let mut y = input.max_inflation;
 
+	// The algorithm divide the curve in segment with vertical len and horizontal len less
+	// than `max_length`. This is not very accurate in case of very consequent steep.
 	while delta_y != 0 {
 		let next_y = y - delta_y;
 

substrate/srml/staking/reward-curve/test/Cargo.toml

@@ -1,9 +0,0 @@
-[package]
-name = "srml-staking-reward-curve-test"
-version = "2.0.0"
-authors = ["Parity Technologies <admin@parity.io>"]
-edition = "2018"
-
-[dependencies]
-srml-staking-reward-curve = { path = ".." }
-sr-primitives = { path = "../../../../core/sr-primitives" }