🎉 Tekton Pipelines with Graphs; without init containers! 🎉

This is the first dogfood released version of Tekton Pipelines, where the images were built, pushed and tagged using a Task!

Changes

✨ Allow default system namespace to be overridden using an env var (#427)
✨ Use DAG (graph) based execution for Pipelines instead of linear one (#473, #578 )
✨ Use truncated base TaskRun name for lookup (#565)
✨ The containers executing the Task steps are changed from using InitContainers to Containers in the TaskRun pod. This is achieved by wrapping each container by a custom binary entrypoint to manage the order of the steps. As such, it is always recommended to explicitly specify a command for a Task step. If a step's image is in a private registry, a ServiceAccount with ImagePullSecrets should be provided in the Task (#564, #620, #634, #647, #686, #687)
✨ Pipeline doesn't depend on knative/build anymore 💃 (#636, #648)
✨ Update taskrun/pipelinerun timeout logic to not rely on resync behavior (#621, #674, #681)
✨ cmd/git-init: check for errors or at least log them (#677)

🐛 Make sure TaskSpec step container names aren't too long (#550)
🐛 Arbitrary git commits can now be specified in Git PipelineResources (previously it only supported commits which can be git fetch-ed) (#555)
🐛 PipelineResources storage GCS for directories now preserves directory structures during copies. (#566)
🐛 Updates tekton-pipelines-admin clusterrole to have full access to deployments/finalizers (#572)
🐛 Container names must end with an alphanumeric character (#580)
🐛 ServiceAccount without ImagePullSecrets should not fail to fetch (#585)
🐛 Fixes RBAC permissions for task and pipeline runs for openshift (#583)
🐛 Port duplicate pod test from knative/build 🏗 (#603)
🐛 Use full command field for internal containers (#605)

🔨 Remove the logsURL field from TaskRun status. This field was never populated and was leftover from the original POC version of the API. #107 may add something like this in the future but that design remains TBD (#563)
⏫ Bump kubernetes dependecies to 1.12.6 (#662)

Thanks to these contributors who contributed to v0.2.0!

Extra shout-out for awesome release notes: