Set up Travis & Coveralls

* Drop python3.5 support (see below)
* Pin some dependency versions that were breaking on Travis
* Add badges to README

Python 3.5: some tweaks were needed to get the tests running on
Python 3.5 (mainly async_generator and pathlib/open stuff), but
the tests would hang on Travis. I compiled Python 3.5 locally and
the tests ran fine every time. I tried a few esoteric debug
techniques like `timeout -s SIGINT 5 pytest` which should kill
pytest during the hung test and print a stack trace, but that
didn't work so I gave up and just removed Python 3.5 support. I'm
happy to add it back later if somebody can figure it out, but I
can't afford to keep toying with it right now.

.gitignore

@@ -1,5 +1,7 @@
+.coverage
 .pytest_cache
 __pycache__
+coverage.xml
 dist
 examples/fake.*
 trio_websocket.egg-info

.travis.yml

@@ -0,0 +1,20 @@
+language: python
+
+git:
+  depth: 1
+
+matrix:
+  include:
+    - python: 3.6
+    - python: 3.7
+      dist: xenial
+      sudo: true
+
+install:
+  - pip install .[dev]
+
+script:
+  - pytest --cov=trio_websocket
+
+after_success:
+  - coveralls

README.md

@@ -1,3 +1,9 @@
+[![Build Status](https://img.shields.io/travis/HyperionGray/trio-websocket.svg?style=flat-square)](https://travis-ci.org/HyperionGray/trio-websocket)
+[![Coverage](https://img.shields.io/coveralls/github/HyperionGray/trio-websocket.svg?style=flat-square)](https://coveralls.io/github/HyperionGray/trio-websocket?branch=master)
+[![PyPI](https://img.shields.io/pypi/v/trio-websocket.svg?style=flat-square)](https://pypi.org/project/trio-websocket/)
+[![Python Versions](https://img.shields.io/pypi/pyversions/trio-websocket.svg)]
+![MIT License](https://img.shields.io/github/license/HyperionGray/trio-websocket.svg?style=flat-square)]
+
 # Trio WebSocket
 
 This project implements [the WebSocket

setup.py

@@ -28,21 +28,29 @@
         'Intended Audience :: Developers',
         'Topic :: Software Development :: Libraries',
         'License :: OSI Approved :: MIT License',
-        'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
     ],
+    python_requires=">=3.6",
     keywords='websocket client server trio',
     packages=find_packages(exclude=['docs', 'examples', 'tests']),
     install_requires=[
         'async_generator',
-        'attrs',
+        'attrs>=18.2',
         'ipaddress',
         'trio>=0.8',
         'wsaccel',
         'wsproto',
         'yarl'
     ],
     extras_require={
-        'dev': ['pytest', 'pytest-trio', 'trustme'],
+        'dev': [
+            'coveralls',
+            'pytest>=3.6',
+            'pytest-cov',
+            'pytest-trio',
+            'trustme',
+        ],
     },
     project_urls={
         'Bug Reports': 'https://github.com/HyperionGray/trio-websocket/issues',

trio_websocket/__init__.py

@@ -4,7 +4,7 @@
 import ssl
 from functools import partial
 
-from async_generator import async_generator, yield_, asynccontextmanager
+from async_generator import asynccontextmanager
 import attr
 from ipaddress import ip_address, IPv4Address, IPv6Address
 import trio
@@ -23,7 +23,6 @@
 
 
 @asynccontextmanager
-@async_generator
 async def open_websocket(host, port, resource, use_ssl):
     '''
     Open a WebSocket client connection to a host.
@@ -45,7 +44,7 @@ async def open_websocket(host, port, resource, use_ssl):
         connection = await connect_websocket(new_nursery, host, port, resource,
             use_ssl)
         async with connection:
-            await yield_(connection)
+            yield connection
 
 
 async def connect_websocket(nursery, host, port, resource, use_ssl):