remove aiohttp-client from example-http env

Author: joshuahlang

tox.ini

@@ -71,7 +71,6 @@ commands_pre =
   example-basic-tracer: pip install -e {toxinidir}/opentelemetry-sdk
   example-http: pip install -e {toxinidir}/opentelemetry-api
   example-http: pip install -e {toxinidir}/opentelemetry-sdk
-  example-http: pip install -e {toxinidir}/ext/opentelemetry-ext-aiohttp-client
   example-http: pip install -e {toxinidir}/ext/opentelemetry-ext-http-requests
   example-http: pip install -e {toxinidir}/ext/opentelemetry-ext-wsgi
   example-http: pip install -r {toxinidir}/examples/http/requirements.txt