1.0.0-alpha.21

• Fixes a bug with parallel modules when they return a null enumerable.
• Adds AnalyzeCSharp.WithCompilationAssemblyName() to set the name of the module compilation (#71).
• Adds a metadata key "Compilation" to AnalyzeCSharp output documents to get the Roslyn Compilation from the module (#71).
• Adds IConfig.EnsureNonNull() and IConfig.EnsureNonDocument() extensions to simplify config parameter checks.
• Refactors many of the configuration methods in AnalyzeCSharp to take configs instead of atomic values.
• Ensures namespace documents from AnalyzeCSharp contain the "ContainingAssembly" metadata (#70).
• Build script support for non-Windows platforms via a new build.sh (#65, thanks @khalidabuhakmeh).
• Adds a Config<TValue>.MakeEnumerable() extension to transform a config into an enumerable value.
• Adds a common MultiConfigModuleBase for MultiConfigModule and ParallelMultiConfigModule.
• Adds CombineConfig helper methods to MultiConfigModuleBase to help with combining config values during configuration.
• Refactors several of the StartProcess configuration methods to take configs.