Add a top-level Makefile

So we have single entry points to install/check everything

python/Makefile

@@ -0,0 +1,11 @@
+# Install the package (needs root privileges)
+install:
+	pip install ./crankshaft --upgrade
+
+# Test from source code
+test:
+	(cd crankshaft && nosetests test/)
+
+# Test currently installed package
+testinstalled:
+	nosetests crankshaft/test/