Add FlexMeasures plugins, USEF protocol, and Cariflex simulator

- flexmeasures-entsoe: ENTSO-E data plugin
- flexmeasures-weather: Weather data plugin
- USEF Flex Trading Protocol PDF (2.4MB)
- Cariflex simulator (publishes to Redis)
- Dashboard Grafana updated with correct InfluxDB queries
- All tools extracted in /tools/

tools/flexmeasures-weather/requirements/test.in

@@ -0,0 +1,10 @@
+-c app.txt
+
+pytest
+pytest-flask
+pytest-sugar
+pytest-cov
+# lets tests run successfully in containers
+fakeredis
+# required with fakeredis, maybe because we use rq
+lupa