Merged in chris_hemingway/flatcam/pip_requirements_txt (pull request #12)

Add requirements.txt for pip

requirements.txt

@@ -0,0 +1,9 @@
+# This file contains python only requirements to be installed with pip
+# Python pacakges that cannot be installed with pip (e.g. PyQT4) are not included.
+# Usage: pip install -r requirements.txt
+numpy>=1.8
+matplotlib>=1.3.1
+shapely>=1.3
+simplejson
+rtree
+scipy