Fix colors on windows

* Initialize ansi_term if we're on windows
* Silence build warning on non-unix targets
* Update ansi-term which has windows specific fixes (and assert_cli while I'm at it)

src/main.rs

@@ -11,7 +11,16 @@ mod utils;
 
 static DEFAULT_NUMBER_OF_LINES: usize = 20;
 
+#[cfg(windows)]
+fn init_color() {
+    ansi_term::enable_ansi_support().expect("Couldn't enable color support");
+}
+
+#[cfg(not(windows))]
+fn init_color() {}
+
 fn main() {
+    init_color();
     let def_num_str = DEFAULT_NUMBER_OF_LINES.to_string();
     let options = App::new("Dust")
         .about("Like du but more intuitive")

src/utils/platform.rs

@@ -1,5 +1,6 @@
 use jwalk::DirEntry;
 
+#[cfg(target_family = "unix")]
 fn get_block_size() -> u64 {
     // All os specific implementations of MetatdataExt seem to define a block as 512 bytes
     // https://doc.rust-lang.org/std/os/linux/fs/trait.MetadataExt.html#tymethod.st_blocks