Fixing backticks to remove errors from cloud foundry push

Noticed errors in the logs when pushing to bluemix (using cf). Issue is related to unescaped backticks in comments echoed. Replaced backticks with single quotes.

```
Prepend proper path buildpack use.
Switch to the repo's context.
Experimental pre_compile hook.
/tmp/buildpacks/heroku-buildpack-python/bin/compile: line 110: setup.py: command not found
If no requirements given, assume .
If no runtime given, assume default version.
-----> No runtime.txt provided; assuming python-2.7.4.
# Purge old-style virtualenvs.
Restore old artifacts from the cache.
/tmp/buildpacks/heroku-buildpack-python/bin/compile: line 139: .heroku: command not found
Create set-aside  folder.
Install Python.
```