Allow using environment variables for project url and commit.

lakefile.lean

@@ -48,7 +48,10 @@ def getGithubBaseUrl (gitUrl : String) : String := Id.run do
 /--
 Obtain the Github URL of a project by parsing the origin remote.
 -/
-def getProjectGithubUrl (directory : System.FilePath := "." ) : IO String := do
+def getProjectGithubUrl (directory : System.FilePath := ".") : IO String := do
+  match (<- IO.getEnv "GIT_ORIGIN_URL") with
+  | some url => return url
+  | none =>
     let out ← IO.Process.output {
       cmd := "git",
       args := #["remote", "get-url", "origin"],
@@ -61,7 +64,10 @@ def getProjectGithubUrl (directory : System.FilePath := "." ) : IO String := do
 /--
 Obtain the git commit hash of the project that is currently getting analyzed.
 -/
-def getProjectCommit (directory : System.FilePath := "." ) : IO String := do
+def getProjectCommit (directory : System.FilePath := ".") : IO String := do
+  match (<- IO.getEnv "GIT_REVISION") with
+  | some rev => return rev
+  | none =>
     let out ← IO.Process.output {
       cmd := "git",
       args := #["rev-parse", "HEAD"]