Get rid of Travis CI and switch to GHA

Signed-off-by: Daniel Egger <[email protected]>

Author: therealprof

cortex-m-rt/.github/bors.toml

@@ -1,4 +1,17 @@
 block_labels = ["needs-decision"]
 delete_merged_branches = true
 required_approvals = 1
-status = ["continuous-integration/travis-ci/push"]
+status = [
+  "ci-linux (stable, x86_64-unknown-linux-gnu)",
+  "ci-linux (stable, thumbv6m-none-eabi)",
+  "ci-linux (stable, thumbv7m-none-eabi)",
+  "ci-linux (stable, thumbv7em-none-eabi)",
+  "ci-linux (stable, thumbv7em-none-eabihf)",
+  "ci-linux (stable, thumbv8m.main-none-eabi)",
+  "ci-linux (1.39.0, x86_64-unknown-linux-gnu)",
+  "ci-linux (1.39.0, thumbv6m-none-eabi)",
+  "ci-linux (1.39.0, thumbv7m-none-eabi)",
+  "ci-linux (1.39.0, thumbv7em-none-eabi)",
+  "ci-linux (1.39.0, thumbv7em-none-eabihf)",
+  "ci-linux (1.39.0, thumbv8m.main-none-eabi)"
+]