Merge pull request #8 from softprops/self-update

update rustup before for reliable nightly toolchain tool availability

src/rustup.ts

@@ -14,6 +14,10 @@ export async function install() {
 
     core.debug('rustup is located under: ' + toolPath);
     core.addPath(path.join(toolPath, 'bin'));
+  } else {
+    // update the GitHub managed VM version of rustup
+    // to leverage newer features like "latest latest compatible nightly"
+    await exec.exec('rustup', ['self', 'update']);
   }
 }