Updated nix dependency version to 0.14

Author: drinkdhmo

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "gpio-cdev"
-version = "0.2.0"
+version = "0.2.1"
 authors = ["Paul Osborne <[email protected]>", "Frank Pagliughi <[email protected]>"]
 description = "Linux GPIO Character Device Support (/dev/gpiochipN)"
 homepage = "https://github.com/posborne/rust-gpio-cdev"
@@ -14,7 +14,7 @@ license = "MIT OR Apache-2.0"
 bitflags = "1.0"
 error-chain = "0.12"
 libc = "0.2"
-nix = "0.11"
+nix = "0.14"
 
 [dev-dependencies]
 quicli = "0.2"