Update peg requirement from ~0.6 to ~0.7

Updates the requirements on [peg](https://github.com/kevinmehall/rust-peg) to permit the latest version.
- [Release notes](https://github.com/kevinmehall/rust-peg/releases)
- [Commits](https://github.com/kevinmehall/rust-peg/compare/0.6.0...0.7.0)

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

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

edn/Cargo.toml

@@ -12,13 +12,13 @@ readme = "./README.md"
 [dependencies]
 chrono = "~0.4"
 itertools = "~0.9"
-num = "~0.3"
+num = "~0.4"
 ordered-float = "~2.5"
 pretty = "~0.10"
 uuid = { version = "~0.8", features = ["v4", "serde"] }
 serde = { version = "~1.0", optional = true }
 serde_derive = { version = "~1.0", optional = true }
-peg = "~0.6"
+peg = "~0.7"
 
 [dev-dependencies]
 serde_test = "~1.0"