Release v0.1.0

This adds #[derive(InfluxDbWriteable)] for Structs, fixes escaping for the line-protocol and improves timestamp handling.

Added

• #[derive(InfluxDbWriteable)] for deriving struct writing (@msrd0)

Changed

• Change type of timestamp-variants to u128 (@mario-kr)

Fixed

• Use rfc3339 as default timestamp precision (@zjhmale)