create and publish github release (#1216)

* create and publish github release

* creates a tarball of 'lotus', 'lotus-storage-miner' and
'lotus-seal-worker' for darwin and linux
* computes and saves IPFS CID and sha512sum for each architecture
* creates a github release and uploads all artifacts
* triggered by tags matching regex /^v\d+\.\d+\.\d+$/ ie. v0.1.0

* add licenses and readme

scripts/build-bundle.sh

@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+set -ex
+
+ARCHS=(
+    "darwin"
+    "linux"
+)
+
+REQUIRED=(
+    "ipfs"
+    "sha512sum"
+)
+for REQUIRE in "${REQUIRED[@]}"
+do
+    command -v "${REQUIRE}" >/dev/null 2>&1 || echo >&2 "'${REQUIRE}' must be installed"
+done
+
+mkdir bundle
+pushd bundle
+
+BINARIES=(
+    "lotus"
+    "lotus-storage-miner"
+    "lotus-seal-worker"
+)
+
+export IPFS_PATH=`mktemp -d`
+ipfs init
+ipfs daemon &
+PID="$!"
+trap "kill -9 ${PID}" EXIT
+sleep 30
+
+for ARCH in "${ARCHS[@]}"
+do
+    mkdir -p "${ARCH}/lotus"
+    pushd "${ARCH}"
+    for BINARY in "${BINARIES[@]}"
+    do
+        cp "../../${ARCH}/${BINARY}" "lotus/"
+        chmod +x "lotus/${BINARY}"
+    done
+
+    tar -zcvf "../lotus_${CIRCLE_TAG}_${ARCH}-amd64.tar.gz" lotus
+    popd
+    rm -rf "${ARCH}"
+
+    sha512sum "lotus_${CIRCLE_TAG}_${ARCH}-amd64.tar.gz" | cut -d" " -f1 > "lotus_${CIRCLE_TAG}_${ARCH}-amd64.tar.gz.sha512"
+
+    ipfs add "lotus_${CIRCLE_TAG}_${ARCH}-amd64.tar.gz" | cut -d" " -f2 > "lotus_${CIRCLE_TAG}_${ARCH}-amd64.tar.gz.cid"
+done
+popd