Update dependencies

Gopkg.lock

@@ -9,20 +9,9 @@
   pruneopts = "UT"
   revision = "591f970eefbbeb04d7b37f334a0c4c3256e32876"
 
-[[projects]]
-  digest = "1:cf31692c14422fa27c83a05292eb5cbe0fb2775972e8f1f8446a71549bd8980b"
-  name = "github.com/pkg/errors"
-  packages = ["."]
-  pruneopts = "UT"
-  revision = "ba968bfe8b2f7e042a574c888954fccecfa385b4"
-  version = "v0.8.1"
-
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  input-imports = [
-    "github.com/DHowett/go-plist",
-    "github.com/pkg/errors",
-  ]
+  input-imports = ["github.com/DHowett/go-plist"]
   solver-name = "gps-cdcl"
   solver-version = 1

Gopkg.toml

@@ -29,10 +29,6 @@
   branch = "master"
   name = "github.com/DHowett/go-plist"
 
-[[constraint]]
-  name = "github.com/pkg/errors"
-  version = "0.8.1"
-
 [prune]
   go-tests = true
   unused-packages = true