Add hydra configuration

hydra.json

@@ -0,0 +1,29 @@
+{
+  "enabled": 1,
+  "hidden": true,
+  "description": "Jobsets",
+  "nixexprinput": "src",
+  "nixexprpath": "jobsets.nix",
+  "checkinterval": 300,
+  "schedulingshares": 100,
+  "enableemail": false,
+  "emailoverride": "",
+  "keepnr": 10,
+  "inputs": {
+    "src": {
+      "type": "git",
+      "value": "https://github.com/haskell-nix/hnix.git master",
+      "emailresponsible": false
+    },
+    "nixpkgs": {
+      "type": "git",
+      "value": "https://github.com/NixOS/nixpkgs-channels nixos-unstable",
+      "emailresponsible": false
+    },
+    "prs": {
+      "type": "githubpulls",
+      "value": "haskell-nix hnix",
+      "emailresponsible": false
+    }
+  }
+}

release.nix

@@ -0,0 +1,16 @@
+{}:
+let matrix = [
+      { compiler = "ghc802"; doStrict = false; doTracing = false; }
+      { compiler = "ghc802"; doStrict = false; doTracing = true;  }
+      { compiler = "ghc822"; doStrict = true;  doTracing = false; }
+      { compiler = "ghc822"; doStrict = true;  doTracing = true;  }
+      { compiler = "ghc843"; doStrict = false; doTracing = false; }
+      { compiler = "ghc843"; doStrict = false; doTracing = true;  }
+
+      # Broken
+      # { compiler = "ghcjs";  doStrict = false; doTracing = false; }
+    ];
+    boolToString = x: if x then "true" else "false";
+    nameForConfig = {compiler, doStrict, doTracing}: builtins.concatStringsSep "-"
+      [ compiler (boolToString doStrict) (boolToString doTracing) ];
+in builtins.listToAttrs (map (args: { name = nameForConfig args; value = import ./. args; }) matrix)