Update approx requirement from 0.4 to 0.5

Updates the requirements on [approx](https://github.com/brendanzab/approx) to permit the latest version.
- [Commits](brendanzab/approx@v0.4.0...v0.5.1)

---
updated-dependencies:
- dependency-name: approx
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.toml

@@ -57,7 +57,7 @@ ctrlc = "3.4"
 
 [dev-dependencies]
 criterion = "0.5"
-approx = "0.4"
+approx = "0.5"
 argmin_testfunctions = "0.2"
 
 [workspace]

doe/Cargo.toml

@@ -32,7 +32,7 @@ serde = { version = "1", optional = true }
 [dev-dependencies]
 criterion = "0.5"
 serde_json = "1"
-approx = "0.4"
+approx = "0.5"
 
 [[bench]]
 name = "lhs"

ego/Cargo.toml

@@ -61,7 +61,7 @@ derive_more = "0.99"
 
 [dev-dependencies]
 criterion = "0.5"
-approx = "0.4"
+approx = "0.5"
 argmin_testfunctions = "0.2"
 serial_test = "3.1.0"
 

gp/Cargo.toml

@@ -48,7 +48,7 @@ finitediff = { version = "0.1", features = ["ndarray"] }
 [dev-dependencies]
 criterion = "0.5"
 serde_json = "1"
-approx = "0.4"
+approx = "0.5"
 argmin_testfunctions = "0.2"
 
 [[bench]]

moe/Cargo.toml

@@ -55,7 +55,7 @@ typetag = { version = "0.2", optional = true }
 
 [dev-dependencies]
 criterion = "0.5"
-approx = "0.4"
+approx = "0.5"
 ndarray-npy = "0.8"
 ndarray-csv = "0.5"
 csv = "1.1"