dependencies bump

Cargo.toml

@@ -5,7 +5,7 @@ categories = ["os"]
 keywords = ["upgrade", "update"]
 license-file = "LICENSE"
 repository = "https://github.com/r-darwish/topgrade"
-version = "2.6.0"
+version = "2.7.0"
 authors = ["Roey Darwish Dror <roey.ghost@gmail.com>"]
 exclude = ["doc/screenshot.gif"]
 edition = "2018"
@@ -22,7 +22,7 @@ structopt = "0.2.16"
 log = "0.4.6"
 walkdir = "2.2.7"
 console = "0.7.5"
-self_update_crate = { version = "0.5.1", optional = true, package =  "self_update" }
+self_update_crate = { version = "0.6.0", optional = true, package =  "self_update" }
 lazy_static = "1.3.0"
 rust-ini = "0.13.0"
 chrono = "0.4.6"
@@ -34,7 +34,7 @@ pretty_env_logger = "0.3.0"
 glob = "0.3.0"
 
 [target.'cfg(unix)'.dependencies]
-nix = "0.14.0"
+nix = "0.15.0"
 
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3", features = ["wincon"] }