add changelog script (#270)

scripts/changelog.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+SINCE=$1
+RELEASE=$2
+BRANCH="${3:-$(git branch --show-current)}"
+OUTFILE="${4:-changelog.out}"
+
+docker run --rm=true -it -v "$(pwd)":/usr/local/src/your-app -v "pomerium-changelog-cache:/cache" ferrarimarco/github-changelog-generator \
+    --user pomerium --project pomerium \
+    -o "${OUTFILE}" \
+    --no-issues \
+    --max-issues 500 \
+    --usernames-as-github-logins \
+    --release-branch "${BRANCH}" \
+    --future-release "${RELEASE}" \
+    --since-tag "${SINCE}" \
+    --token "${GITHUB_TOKEN}" \
+    --breaking-label "## Breaking" \
+    --enhancement-label "## New" \
+    --bugs-label "## Fixed" \
+    --pr-label "## Changed" \
+    --deprecated-label "## Deprecated" \
+    --removed-label "## Removed" \
+    --security-label "## Security" \
+    --cache-file /cache \
+    --enhancement-labels "improvement,Improvement,enhancement,Enhancement,feature" \
+    --exclude-labels "docs,ci" \
+    --add-sections '{"documentation":{"prefix":"## Documentation","labels":["docs"]}, "dependency":{"prefix":"## Dependency","labels":["dependency","dependencies"]}, "deployment":{"prefix":"## Deployment","labels":["deployment"]}}'