Release S7NetPlus 0.3.0

Release highlights:
- Replace LastErrorCode and LastErrorString with exceptions
- Fix StringEx write support
- Add PDB files with SourceLink to NuGet package
- Increase PDU size to support larger requests (S7-1500)
- Fix String length on write

Release S7NetPlus 0.2.0

Release highlights:
- Async API (PR S7NetPlus#111)
- NetStandard 1.3 (replaces UWP) and 2.0 support (PR S7NetPlus#123, S7NetPlus#142)
- Support for write of multiple DataItems in single request (PR S7NetPlus#121)
- Fixed byte order for short[] / Int16[] (S7NetPlus#126, PR S7NetPlus#127)
- Fixed negotiated PDU size (S7NetPlus#128, PR S7NetPlus#130)
- Added support for float, obsoleted support for double (S7NetPlus#132, PR S7NetPlus#143)
- Fixed invalid TPKT length (PR S7NetPlus#152)
- Added SourceLink support (PR S7NetPlus#155)

Release highlights:

- Store MaxPDUSize after communication setup
- Fix for reading bit and odd number of bytes in ReadMultipleVars
- Documentation improvements
- Support for reading S7 strings with header
- Fix for REAL conversion

0.1.8

Fix UWP build

Nuget 0.1.6