Support readthedocs

This is mostly copied from fpylll

Author: jdemeyer

readthedocs-conda.yml

@@ -0,0 +1,4 @@
+channels:
+  - conda-forge
+dependencies:
+  - pari

readthedocs.yml

@@ -0,0 +1,5 @@
+conda:
+    file: readthedocs-conda.yml
+python:
+    version: 2.7
+    pip_install: true

requirements.txt

@@ -0,0 +1,4 @@
+setuptools
+Cython
+cysignals
+Sphinx>=1.6

setup.py

@@ -1,11 +1,23 @@
+#!/usr/bin/env python
+
+import os
 import sys
+
+if "READTHEDOCS" in os.environ:
+    # When building with readthedocs, install the dependencies too.
+    # See https://github.com/rtfd/readthedocs.org/issues/2776
+    for reqs in ["requirements.txt"]:
+        if os.path.isfile(reqs):
+            from subprocess import check_call
+            check_call([sys.executable, "-m", "pip", "install", "-r", reqs])
+
+
 from setuptools import setup
 from distutils.command.build_ext import build_ext as _build_ext
 from setuptools.command.bdist_egg import bdist_egg as _bdist_egg
 from setuptools.extension import Extension
 
 
-
 # Adapted from Cython's new_build_ext
 class build_ext(_build_ext):
     def finalize_options(self):