0.1.1: GH-11 Add Deb package generation support

Update required CMakeLists boost version
Add Debian package generation.
Running cpack -GDEB yields a debian package:

```
dpkg -I dist/toolbox-cpp-snapshot-x86_64.deb
 new debian package, version 2.0.
 size 8005316 bytes: control archive=2299 bytes.
     274 bytes,    11 lines      control
    5200 bytes,    69 lines      md5sums
 Architecture: amd64
 Depends: boost (>=1.67)
 Description: Toolbox - The Reactive C++ Toolbox
 Homepage: https://www.reactivemarkets.com
 Maintainer: [email protected]
 Package: toolbox-cpp
 Priority: optional
 Section: devel
 Version: snapshot
 Installed-Size: 23438
```