fixed dependencies

Cargo.toml

 [package]
 name = "btui"
-version = "0.6.5"
+version = "0.6.6"
 edition = "2018"
 authors = ["Moritz Sokoll <moritz@sokoll.com>"]
 license = "MIT"
@@ -17,11 +17,8 @@ crate-type = ["lib"]
 required-features = []
 doc = true
 
-[dependencies]
-ncurses = {version = "5.101.0", optional = true}
-
 [features]
 default = ["core", "linux", "pbar"]
 core = []
-linux = ["core", "ncurses"]
+linux = ["core"]
 pbar = ["linux"]