updates

libmarlin/Cargo.toml

@@ -19,3 +19,10 @@ serde_json         = { version = "1", optional = true }
 
 [features]
 json = ["serde_json"]
+
+[dev-dependencies]
+# for temporary directories in config_tests.rs and scan_tests.rs
+tempfile = "3"
+
+# you already have rusqlite in [dependencies], so scan_tests.rs
+# can just use rusqlite::Connection, no need to repeat it here.