Make hiredis and optional dependency (resolves #917)

CHANGES/917.feature

@@ -0,0 +1 @@
+Make hiredis an optional dependency.

docs/getting-started.md

@@ -6,15 +6,12 @@
 pip install aioredis
 ```
 
-This will install `aioredis`, alongside `hiredis` and `async-timeout`.
+This will install `aioredis`, `async-timeout`.
 
-### Without Dependencies
-
-If you find yourself in a situation where you cannot support `hiredis` in your
-application, you can install aioredis without that dependency:
+### With hiredis
 
 ```shell
-pip install --no-deps aioredis async-timeout
+pip install aioredis[hiredis]
 ```
 
 ### Installing from Git

setup.py

@@ -39,7 +39,7 @@ def read_version():
 setup(
     name="aioredis",
     version=read_version(),
-    description=("asyncio (PEP 3156) Redis support"),
+    description="asyncio (PEP 3156) Redis support",
     long_description="\n\n".join((read("README.md"), read("CHANGES.md"))),
     long_description_content_type="text/markdown",
     classifiers=classifiers,
@@ -49,9 +49,11 @@ def read_version():
     packages=find_packages(exclude=["tests"]),
     install_requires=[
         "async-timeout",
-        'hiredis>=1.0; implementation_name=="cpython"',
         "typing-extensions",
     ],
+    extras_require={
+        "hiredis": 'hiredis>=1.0; implementation_name=="cpython"',
+    },
     python_requires=">=3.6",
     include_package_data=True,
 )