Refactor imagebumper + bump Tempest

Tempest is branchless, so we can bump to
the latest version of Tempest.

Skip-Release-Notes

Change-Id: I08aa5ce1b293d1e1e23735281dedc5c14473b88a
diff --git a/Cargo.lock b/Cargo.lock
index 91bb852..9232d84 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -118,9 +118,13 @@
 name = "atmosphere"
 version = "0.0.0"
 dependencies = [
+ "clap",
+ "env_logger",
  "git2",
  "git2-hooks",
+ "imagebumper",
  "indoc",
+ "log",
  "md5",
  "regex",
  "reqwest",
@@ -1029,14 +1033,8 @@
 version = "0.1.0"
 dependencies = [
  "async-trait",
- "clap",
- "env_logger",
  "gitea-sdk",
- "log",
  "octocrab",
- "regex",
- "reqwest",
- "serde_json",
  "tokio",
  "url",
 ]