Fix apt-get command to upgrade bazel
`apt-get upgrade` will upgrade all packages to their latest versions; to upgrade bazel alone, use `install`.
Closes
@@ -103,5 +103,5 @@ sudo apt-get update && sudo apt-get install bazel
Once installed, you can upgrade to a newer version of Bazel with the following command:
```bash
-sudo apt-get upgrade bazel
+sudo apt-get install --only-upgrade bazel
```
