Create a json-integration feature flag and disable building the CLI program without it.

Cargo.toml

@@ -4,6 +4,10 @@ version = "0.1.0"
 authors = ["Tom Alexander <tom@fizz.buzz>"]
 edition = "2018"
 
+[features]
+default = []
+json-integration = []
+
 [lib]
 name = "duster"
 path = "src/lib.rs"
@@ -11,6 +15,7 @@ path = "src/lib.rs"
 [[bin]]
 name = "duster-cli"
 path = "src/bin.rs"
+required-features = ["json-integration"]
 
 [dependencies]
 nom = { git = "https://github.com/tomalexander/nom.git", branch = "take_until_parser_matches" }