Use the print() function in Makefile.

Use the print() function rather than the print statement in the
Makefile.

Makefile

@@ -2,7 +2,7 @@ PYTHON = python
 PYLINT = pylint
 SETUP = $(PYTHON) setup.py
 PYDOCTOR ?= pydoctor
-ifeq ($(shell $(PYTHON) -c "import sys; print sys.version_info >= (2, 7)"),True)
+ifeq ($(shell $(PYTHON) -c "import sys; print(sys.version_info >= (2, 7))"),True)
 TESTRUNNER ?= unittest
 else
 TESTRUNNER ?= unittest2.__main__