Fix reading coils

Reading more than 8 coils was broken, fixed in this release

Fix bug in write_single_coil callback introduced in prev release

v0.1.3

Fix syntax warning

Use Connection library for automatic reconnects

Kudos to @denvera

Update deps

v0.1.1

update deps

Add Modbus RTU support

Kudos to David Hanson and Troy Nichols

Add more modbus functions

v0.0.3

Bump version number

Initial hex.pm release

0.0.2

Prepare for hex.pm upload