buildGoPackage: remove Go deps file libs.json

After #16017 there were a lot
of comments saying that `nix` would be better than `JSON`
for Go packages dependency sets.
As said in https://github.com/NixOS/nixpkgs/pull/16017#issuecomment-229624046

    > Because of the content-addressable store, if two programs have the
    > same dependency it will already result in the same derivation in
    > the
    > store. Git also has compression in the pack files so it won't make
    > much difference to duplicate the dependencies on disk. And finally
    > most users will just use the binary builds so it won't make any
    > differences to them.

This PR removes `libs.json` file and puts all package dependencies in
theirs `deps.json`.

pkgs/servers/nsq/deps.json

@@ -1,16 +1,83 @@
 [
-  {
-    "include": "../../libs.json",
-    "packages": [
-      "github.com/mreiferson/go-snappystream",
-      "github.com/bitly/go-nsq",
-      "github.com/bitly/go-simplejson",
-      "github.com/blang/semver",
-      "github.com/bmizerany/perks",
-      "github.com/BurntSushi/toml",
-      "github.com/bitly/go-hostpool",
-      "github.com/bitly/timer_metrics",
-      "github.com/mreiferson/go-options"
-    ]
-  }
+    {
+        "goPackagePath": "github.com/mreiferson/go-snappystream",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/mreiferson/go-snappystream",
+            "rev": "028eae7ab5c4c9e2d1cb4c4ca1e53259bbe7e504",
+            "sha256": "0jdd5whp74nvg35d9hzydsi3shnb1vrnd7shi9qz4wxap7gcrid6"
+        }
+    },
+    {
+        "goPackagePath": "github.com/bitly/go-nsq",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/bitly/go-nsq",
+            "rev": "22a8bd48c443ec23bb559675b6df8284bbbdab29",
+            "sha256": "06hrkwk84w8rshkanvfgmgbiml7n06ybv192dvibhwgk2wz2dl46"
+        }
+    },
+    {
+        "goPackagePath": "github.com/bitly/go-simplejson",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/bitly/go-simplejson",
+            "rev": "18db6e68d8fd9cbf2e8ebe4c81a78b96fd9bf05a",
+            "sha256": "0lj9cxyncchlw6p35j0yym5q5waiz0giw6ri41qdwm8y3dghwwiy"
+        }
+    },
+    {
+        "goPackagePath": "github.com/blang/semver",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/blang/semver",
+            "rev": "9bf7bff48b0388cb75991e58c6df7d13e982f1f2",
+            "sha256": "11sinbf942dpyc9wdpidkhmqn438cfp5n8x3xqnmq9aszkld9hy7"
+        }
+    },
+    {
+        "goPackagePath": "github.com/bmizerany/perks",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/bmizerany/perks",
+            "rev": "6cb9d9d729303ee2628580d9aec5db968da3a607",
+            "sha256": "0cdh84hmn21is6hvv6dy9qjdcg9w3l2k8avlk0881a8cqm09s90j"
+        }
+    },
+    {
+        "goPackagePath": "github.com/BurntSushi/toml",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/BurntSushi/toml",
+            "rev": "056c9bc7be7190eaa7715723883caffa5f8fa3e4",
+            "sha256": "0gkgkw04ndr5y7hrdy0r4v2drs5srwfcw2bs1gyas066hwl84xyw"
+        }
+    },
+    {
+        "goPackagePath": "github.com/bitly/go-hostpool",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/bitly/go-hostpool",
+            "rev": "d0e59c22a56e8dadfed24f74f452cea5a52722d2",
+            "sha256": "14ph12krn5zlg00vh9g6g08lkfjxnpw46nzadrfb718yl1hgyk3g"
+        }
+    },
+    {
+        "goPackagePath": "github.com/bitly/timer_metrics",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/bitly/timer_metrics",
+            "rev": "afad1794bb13e2a094720aeb27c088aa64564895",
+            "sha256": "1b717vkwj63qb5kan4b92kx4rg6253l5mdb3lxpxrspy56a6rl0c"
+        }
+    },
+    {
+        "goPackagePath": "github.com/mreiferson/go-options",
+        "fetch": {
+            "type": "git",
+            "url": "https://github.com/mreiferson/go-options",
+            "rev": "7c174072188d0cfbe6f01bb457626abb22bdff52",
+            "sha256": "0ksyi2cb4k6r2fxamljg42qbz5hdcb9kv5i7y6cx4ajjy0xznwgm"
+        }
+    }
 ]