Add GitHub Actions workflow

[jcansdale]

What this PR does

Create a GitHub Actions workflow that does the following:

• Build using .NET Core
• Package using nuget pack
• Test using dotnet test
• Publish to GitHub Package when on master branch
• Bump version to 0.1.5-beta

[codecov]

Codecov Report

Merging #219 into master will not change coverage by %.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #219   +/-   ##
=======================================
  Coverage   82.12%   82.12%           
=======================================
  Files          73       73           
  Lines        2479     2479           
=======================================
  Hits         2036     2036           
  Misses        443      443