Addressed base fixture attribute.
Implement FixtureAttribute

SharedFixtuerAttribute implemented FixtureAttribute.
Addressed more appropriate names.
Remove AttributeUsage declaration

So the declaration is already defined on FixtureAttribute, it is not
needed to define on SharedFixtureAttribute.
Move the properties(Order, Namespace)

This commit moved the properteis from SharedFixtureAttribute to
FixtureAttribute.
Use Attributes derived from FixtureAttribute

This commit used attributes derived from FixtureAttribute instead of using
SharedFixtureAttribute.
Introduced AutoMockFixtureAttribute.
Addressed code analysis errors.
Clarified the XML document.
Rectify the repositories.config file

This commit rectified the repositories.config file because the name of
the test project was changed.
Allow updating only the AutoFixture nuget packages

This project depends on AutoFixture packages as well as Xunit and Moq.
After installing this project nuget package, updating the depended
packages is not valid but updating the packages for AutoFixture is
allowed to keep the lastest packages.
Increment minor version

This is to indicate that introducing FixtureAttribute is new feature.