feat build: Add Repeatr formula for repeatable builds

Adds a formula for Repeatr (http://repeatr.io/) that can be used to
build kontemplate in a repeatable way with pinned dependencies.

Fixes #47

kontemplate.frm

@@ -0,0 +1,83 @@
+inputs:
+  "/": # https://github.com/tklx/base
+    type: "tar"
+    hash: "9nkvYhmJHaeK_Agc3Lm5rg444dSLWDp0Pri-KilHiX3A9Pt4TaQ7RxOj5qMSs6XT"
+    silo: "https://github.com/tklx/base/releases/download/0.1.1/rootfs.tar.xz"
+  "/opt":
+    type: "tar"
+    hash: "gi0Kpb-VH3TK0UBX6YmpuKsrMAUlxicPrY2YvXPo9sBQm_NsD_hKrn7pmc95zrmM"
+    silo: "https://storage.googleapis.com/golang/go1.8.1.linux-amd64.tar.gz"
+  # Kontemplate dependencies!
+  "/go/src/github.com/polydawn/meep":
+    type: "git"
+    hash: "1487840a4bf30270decdc04123c41cdc7a8067c9"
+    silo: "https://github.com/polydawn/meep"
+  "/go/src/github.com/Masterminds/sprig":
+    type: "git"
+    hash: "f5b0ed4a680a0943228155eaf6a77a96ead1bc77"
+    silo: "https://github.com/Masterminds/sprig"
+  "/go/src/github.com/ghodss/yaml":
+    type: "git"
+    hash: "0ca9ea5df5451ffdf184b4428c902747c2c11cd7"
+    silo: "https://github.com/ghodss/yaml"
+  "/go/src/gopkg.in/yaml.v2":
+    type: "git"
+    hash: "cd8b52f8269e0feb286dfeef29f8fe4d5b397e0b"
+    silo: "https://gopkg.in/yaml.v2"
+  "/go/src/gopkg.in/alecthomas/kingpin.v2":
+    type: "git"
+    hash: "7f0871f2e17818990e4eed73f9b5c2f429501228"
+    silo: "https://gopkg.in/alecthomas/kingpin.v2"
+  "/go/src/github.com/alecthomas/template":
+    type: "git"
+    hash: "a0175ee3bccc567396460bf5acd36800cb10c49c"
+    silo: "https://github.com/alecthomas/template"
+  "/go/src/github.com/alecthomas/units":
+    type: "git"
+    hash: "2efee857e7cfd4f3d0138cc3cbb1b4966962b93a"
+    silo: "https://github.com/alecthomas/units"
+  "/go/src/github.com/Masterminds/semver":
+    type: "git"
+    hash: "abff1900528dbdaf6f3f5aa92c398be1eaf2a9f7"
+    silo: "https://github.com/Masterminds/semver"
+  "/go/src/github.com/aokoli/goutils":
+    type: "git"
+    hash: "e57d01ace047c1a43e6a49ecf3ecc50ed2be81d1"
+    silo: "https://github.com/aokoli/goutils"
+  "/go/src/github.com/huandu/xstrings":
+    type: "git"
+    hash: "3959339b333561bf62a38b424fd41517c2c90f40"
+    silo: "https://github.com/huandu/xstrings"
+  "/go/src/github.com/imdario/mergo":
+    type: "git"
+    hash: "d806ba8c21777d504a2090a2ca4913c750dd3a33"
+    silo: "https://github.com/imdario/mergo"
+  "/go/src/github.com/satori/go.uuid":
+    type: "git"
+    hash: "5bf94b69c6b68ee1b541973bb8e1144db23a194b"
+    silo: "https://github.com/satori/go.uuid"
+  "/go/src/golang.org/x/crypto":
+    type: "git"
+    hash: "ab89591268e0c8b748cbe4047b00197516011af5"
+    silo: "https://go.googlesource.com/crypto"
+action:
+  policy: governor
+  command:
+    - "/bin/sh"
+    - "-e"
+    - "-c"
+    - |
+      export PATH="/opt/go/bin:$PATH"
+      export GOROOT=/opt/go
+      export GOPATH=/go
+      echo 'nameserver 8.8.8.8' > /etc/resolv.conf
+      apt-get update && apt-get install -y git ca-certificates
+      mkdir -p /go/src/github.com/tazjin
+      git clone --single-branch --branch v1.0.1 https://github.com/tazjin/kontemplate /go/src/github.com/tazjin/kontemplate
+      cd /go/src/github.com/tazjin/kontemplate
+      ./build-release.sh build
+outputs:
+  "release":
+    type: "dir"
+    mount: "/go/src/github.com/tazjin/kontemplate/release"
+    silo: "file://release"