Add git LFS as a dependency (#170)

Author: ofalvai

step.yml

@@ -39,6 +39,11 @@ is_requires_admin_user: false
 is_always_run: false
 is_skippable: false
 run_if: .IsCI
+deps:
+  brew:
+  - name: git-lfs
+  apt:
+  - name: git-lfs
 toolkit:
   go:
     package_name: github.com/bitrise-steplib/steps-git-clone