Merge pull request #12 from deref/version-bump

Add version bump script

core/VERSION

@@ -1 +1 @@
-2021.07.16_4
+2021.07.19

doc/release.md

@@ -0,0 +1,5 @@
+# Release Process
+
+exo uses GitHub actions to publish a new release of Exo any time the `core/VERSION` file changes. exo follows a (CalVer)[https://calver.org/] versioning scheme in which each release version adheres to the following scheme: `YYYY.MM.DD_MICRO` where the `_MICRO` suffix is only present if there have been multiple releases on a single day.
+
+To trigger a new build, increment the version with: `./scripts/increment-version.sh`.

script/incrment-version.sh

@@ -0,0 +1,21 @@
+#!/bin/env bash
+
+## Updates the version for release.
+
+## TODO: Disallow when there are staged changes
+
+ROOTDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )/.." &> /dev/null && pwd )"
+
+currentversion="$(cat "${ROOTDIR}/core/VERSION")"
+version="$(date -u +'%Y.%m.%d')"
+if [[ "$currentversion" == "${version}"* ]]; then
+    lastbuild="${currentversion#*_}"
+    if [[ "$lastbuild" == "$currentversion" ]]; then
+        version="${version}_1"
+    else
+        version="${version}_$((lastbuild+1))"
+    fi
+fi
+
+echo -n "$version" > "${ROOTDIR}/core/VERSION"
+