Mention Python2.7 requirement in installation.md
@@ -31,12 +31,14 @@ This will be less messy than using `system()` to shell-out
We designed FLOSS to be as easy to use from a client program as from
the command line.
-To install FLOSS as a Python library, you'll need to install a few
+To install FLOSS as a *Python2.7* library, you'll need to install a few
dependencies, and then use `pip` to fetch the FLOSS module.
+:warning: **FLOSS requires Python2.7 due to some of its dependencies.**
+
### Step 1: Install FLOSS module
-Use `pip` to install the FLOSS module to your local
+Use `pip` (Python2.7) to install the FLOSS module to your local
Python environment.
This fetches the library code to your computer, but does not keep
editable source files around for you to hack on.
