CSV upload

According to the API, user is able to remove ONLY own measurements (not cell towers!): http://www.opencellid.org/measure/delete/MEASURE_ID?key=API_KEY

2. Supported column names in uploadCsv method:

• lat
• lon
• mnc
• mcc
• lac
• cellid
• signal level
• create_at
• updated_at
• speed
• direction