Bump version to 3.1.0.pre to prevent confusion with master being 3.0.0 but 3.0.x releases are out.
Bump version to 3.1.0.pre to prevent confusion with master being 3.0.0 but 3.0.x releases are out.

h4ck3rm1k3/rspec-mocks,rspec/rspec-mocks,AEgan/rspec-mocks,zephyr-dev/rspec-mocks,rspec/rspec-mocks,maclover7/rspec-mocks,telekomatrix/rspec-mocks,h4ck3rm1k3/rspec-mocks,zephyr-dev/rspec-mocks,ducthanh/rspec-mocks,edwardpark/rspec-mocks,telekomatrix/rspec-mocks,maclover7/rspec-mocks,rwz/rspec-mocks,ducthanh/rspec-mocks,edwardpark/rspec-mocks,AEgan/rspec-mocks,rwz/rspec-mocks