Add NPM package, debs, rpms and refactor CI/build process

Closes many issues that I'll prune after adding more docs
for users.

ci/container/exec.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+main() {
+  cd "$(dirname "$0")/../.."
+
+  docker build ci/container
+  imageTag="$(docker build -q ci/container)"
+  docker run \
+    --rm \
+    -e CI \
+    -e GITHUB_TOKEN \
+    -e TRAVIS_TAG \
+    -e NPM_TOKEN \
+    -v "$(yarn cache dir):/usr/local/share/.cache/yarn/v6" \
+    $(if [[ -f ~/.npmrc ]]; then echo -v "$HOME/.npmrc:/root/.npmrc"; fi) \
+    -v "$PWD:/repo" \
+    -w /repo \
+    $(if [[ -t 0 ]]; then echo -it; fi) \
+    "$imageTag" \
+    "$*"
+}
+
+main "$@"