Update to buildpack API 0.10, invoke processes via bash (#205)

* Update to buildpack API 0.10, update to libcnb 0.18, invoke via bash

* Drop stacks from buildpack.toml (no longer supported)

* Cleanup in gitignore

* Update changelog with note about Buildpack API 0.10

* Use String::from to match existing style

* Move user provided command to args[0]

* Update changelog with implicit changes from buildpack api 0.10

* Add integration test for argument overrides

* Remove trailing comma after last element in `vec![]` usages

---------

Co-authored-by: Ed Morley <501702+edmorley@users.noreply.github.com>

Author: joshwlewis

.gitignore

@@ -1,3 +1,5 @@
 /target
+/packaged
+.tool-versions
 .idea
 .DS_Store

CHANGELOG.md

@@ -7,6 +7,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Update to Buildpack API 0.10. ([#205](https://github.com/heroku/procfile-cnb/pull/205)
+    - All launch processes are now wrapped in `bash -c` instead of using CNB's `direct = false` directive, which is no longer available.
+    - `.profile` and `.profile.d` scripts will no longer be automatically sourced.
+    - CNB Lifecycle 0.17 or newer is now required.
+
 ## [2.0.2] - 2023-10-24
 
 ### Changed