Fix: flake8 tests

    flake8 runtests: commands[0] | flake8 influxdb
    influxdb/client.py:73:1: W293 blank line contains whitespace
    influxdb/client.py:94:17: F841 local variable 'total_batches' is assigned to but never used
    influxdb/client.py:97:26: E128 continuation line under-indented for visual indent
    influxdb/client.py:98:26: E128 continuation line under-indented for visual indent
    influxdb/client.py:101:25: E128 continuation line under-indented for visual indent
    ERROR: InvocationError: '......./gits/influxdb-python/.tox/flake8/bin/flake8 influxdb'