chore: remove examples

Examples haven't been updated in ages, and the last remaining example
only uses Streamlink's URL resolver, and not any of Streamlink's stream
implementations, so it's a rather useless example of third party code.

MANIFEST.in

@@ -6,7 +6,6 @@ include *requirements.txt
 
 recursive-include completions *
 recursive-include docs *
-recursive-include examples *
 recursive-include tests *
 
 prune docs/_build

examples/opencv-face.py

@@ -1,77 +0,0 @@
-#!/usr/bin/env python3
-import logging
-import sys
-import streamlink
-import os.path
-
-try:
-    import cv2
-except ImportError:
-    sys.stderr.write("This example requires opencv-python is installed")
-    raise
-
-log = logging.getLogger(__name__)
-GREEN = (0, 255, 0)
-
-
-def stream_to_url(url, quality='best'):
-    streams = streamlink.streams(url)
-    if streams:
-        return streams[quality].to_url()
-    else:
-        raise ValueError("No streams were available")
-
-
-def detect_faces(cascade, frame, scale_factor=1.1, min_neighbors=5):
-    frame_copy = frame.copy()
-    frame_gray = cv2.cvtColor(frame_copy, cv2.COLOR_BGR2GRAY)
-
-    faces = cascade.detectMultiScale(frame_gray, scaleFactor=scale_factor, minNeighbors=min_neighbors)
-
-    for (x, y, w, h) in faces:
-        cv2.rectangle(frame_copy, (x, y), (x + w, y + h), GREEN, 1)
-
-    return frame_copy
-
-
-def main(url, quality='best', fps=30.0):
-    face_cascade = cv2.CascadeClassifier(os.path.join(cv2.haarcascades, 'haarcascade_frontalface_default.xml'))
-
-    stream_url = stream_to_url(url, quality)
-    log.info("Loading stream {0}".format(stream_url))
-    cap = cv2.VideoCapture(stream_url)
-
-    frame_time = int((1.0 / fps) * 1000.0)
-
-    while True:
-        try:
-            ret, frame = cap.read()
-            if ret:
-                frame_f = detect_faces(face_cascade, frame, scale_factor=1.2)
-                cv2.imshow('frame', frame_f)
-                if cv2.waitKey(frame_time) & 0xFF == ord('q'):
-                    break
-            else:
-                break
-        except KeyboardInterrupt:
-            break
-
-    cv2.destroyAllWindows()
-    cap.release()
-
-
-if __name__ == "__main__":
-    import argparse
-    logging.basicConfig(level=logging.INFO)
-
-    parser = argparse.ArgumentParser(description="Face detection on streams via Streamlink")
-    parser.add_argument("url", help="Stream to play")
-    parser.add_argument("--stream-quality", help="Requested stream quality [default=best]",
-                        default="best", dest="quality")
-    parser.add_argument("--fps", help="Play back FPS for opencv [default=30]",
-                        default=30.0, type=float)
-
-    opts = parser.parse_args()
-
-    main(opts.url, opts.quality, opts.fps)
-

setup.cfg

@@ -65,7 +65,6 @@ extend-exclude =
   dist/,
   docs/conf.py,
   env/,
-  examples/,
   src/streamlink/packages/,
   src/streamlink_cli/packages/,
   venv/,