Update deb package to include dotnet prerequisites for ubuntu

[asavaritayal]

From @arerlend on April 30, 2018 19:47

Running with bash via Ubuntu 16.04 subsystem for Windows.

Followed instructions here: https://github.com/Azure/azure-functions-docker-python-sample/wiki/Getting-started-using-Functions-Core-Tools.

Downloaded linux zip file from https://ci.appveyor.com/project/appsvc/azure-functions-cli/build/2.0.1.294/artifacts

Upon using binaries to run func init . --worker-runtime python (or any other call to func), I get the following errors:
Failed to load X{z�, error: libunwind.so.8: cannot open shared object file: No such file or directory
Failed to bind to CoreCLR at '/mnt/c/Users/Administrator/dev/soh-local/func_venv_bash/linux_functions/libcoreclr.so'

Fixed by running apt-get install libunwind8

Copied from original issue: Azure/azure-functions-docker-python-sample#10

[asavaritayal]

@ahmelsayed

[ahmelsayed]

there are few dependencies for self contained dotnet apps on Ubuntu. https://docs.microsoft.com/en-us/dotnet/core/linux-prerequisites?tabs=netcore2x#ubuntu

@watashiSHUN we should add these prerequisites to the deb package to match what dotnet package does.

If you're downloading the binaries directly you should install the prerequisites

[watashiSHUN]

libunwind is removed from dotnet core 2.1: PowerShell/PowerShell#6964, so using azure-functions-core-tools >= beta.29 should resolve this issue