Disable symbol publish (server inaccessible)

Publish symbols separately to avoid auth error

Merge pull request heaths#8 from heaths/develop

Build only PRs and publish symbols

Merge pull request heaths#7 from heaths/develop

Output full MD5 hash for MSIHashParts

Update README with installation instructions

Resolves issue heaths#2

Make sure the build number is always valid

Tags created by GitVersion cause the BuildMetaData to be empty.

Stop building after new tags are pushed

Every push of 'master' kicked off a second build when a tag was created to
push the release.

Ensure that the output paths are created

GitVersion was not ensuring that the IntermediateOutputPath existed before
generating source code under it.

Build nuget package for psgallery deployment

Starting new development