Start on US-FL SEC parser, just solar

background in electricitymaps#1713. example output:

```json
[{
  'zoneKey': 'US-SEC'
  'datetime': "2019-07-02T11:00:00Z",
  'production': {'solar': 0.0125},
  'source': 'apps.seminole.coop',
 }, {
  'zoneKey': 'US-SEC'
  'datetime': "2019-07-02T12:00:00Z",
  'production': {'solar': 0.1269},
  'source': 'apps.seminole.coop',
 },
 ...
]
```

parsers/US_SEC.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+
+"""Parser for the Seminole Electric Cooperative in Florida, USA.
+
+https://github.com/tmrowco/electricitymap-contrib/issues/1713
+"""
+
+import logging
+from datetime import timezone
+
+import pandas as pd
+
+
+def fetch_solar(session=None, logger=logging.getLogger(__name__)):
+    url = 'http://apps.seminole.coop/db/cs/render.ashx?ItemPath=/Applications/Solar+Dashboard/Cooperative+Solar+-+Data&Format=EXCEL&rptHDInterval=Day&rptHDOffset=0'
+    df = pd.read_excel(url, sheet_name='Hourly', skiprows=[0])
+
+    return [{
+        'zoneKey': 'US_SEC',
+        'datetime': row['Date/Time (UTC)'].to_pydatetime().replace(tzinfo=timezone.utc),
+        'production': {'solar': row['kW'] / 1000.0},
+        'source': 'apps.seminole.coop',
+    } for _, row in df.iterrows()]
+
+
+
+if __name__ == '__main__':
+    """Main method, not used by the ElectricityMap backend, just for testing."""
+
+    import json, pprint
+    print('fetch_solar() ->')
+    print(pprint.pprint(fetch_solar()))