Switch from kingpin to cobra

This enables easier use of sub-commands for flexibility

Gopkg.lock

@@ -2,25 +2,10 @@
 
 
 [[projects]]
-  branch = "master"
-  name = "github.com/alecthomas/template"
-  packages = [
-    ".",
-    "parse"
-  ]
-  revision = "a0175ee3bccc567396460bf5acd36800cb10c49c"
-
-[[projects]]
-  branch = "master"
-  name = "github.com/alecthomas/units"
+  name = "github.com/inconshreveable/mousetrap"
   packages = ["."]
-  revision = "2efee857e7cfd4f3d0138cc3cbb1b4966962b93a"
-
-[[projects]]
-  name = "github.com/davecgh/go-spew"
-  packages = ["spew"]
-  revision = "346938d642f2ec3594ed81d874461961cd0faa76"
-  version = "v1.1.0"
+  revision = "76626ae9c91c4f2a10f34cad8ce83ea42c93bb75"
+  version = "v1.0"
 
 [[projects]]
   branch = "master"
@@ -34,26 +19,20 @@
   revision = "3fdea8d05856a0c8df22ed4bc71b3219245e4485"
 
 [[projects]]
-  name = "github.com/pmezard/go-difflib"
-  packages = ["difflib"]
-  revision = "792786c7400a136282c1664665ae0a8db921c6c2"
-  version = "v1.0.0"
-
-[[projects]]
-  name = "github.com/stretchr/testify"
-  packages = ["assert"]
-  revision = "f35b8ab0b5a2cef36673838d662e249dd9c94686"
-  version = "v1.2.2"
-
-[[projects]]
-  name = "gopkg.in/alecthomas/kingpin.v2"
+  branch = "master"
+  name = "github.com/spf13/cobra"
   packages = ["."]
-  revision = "947dcec5ba9c011838740e680966fd7087a71d0d"
-  version = "v2.2.6"
+  revision = "a114f312e075f65bf30d6d9a1430113f857e543b"
+
+[[projects]]
+  name = "github.com/spf13/pflag"
+  packages = ["."]
+  revision = "583c0c0531f06d5278b7d917446061adc344b5cd"
+  version = "v1.0.1"
 
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "8073c00a23b0d2ae4957e488d26c76aa22aa6351c4e2b005051d532ecd8c9d66"
+  inputs-digest = "c0b2f6395de968a560dc5faf28b8ab9729f29746c0393e492998461166f08ce3"
   solver-name = "gps-cdcl"
   solver-version = 1