Release v1.0.0-beta5

new features:

• support [expr for k, v <- container, init; cond]
• support return {x.score for x <- a, x.name == name}
• support .spx/.gmx files (see #762)
• TestErrImport

changes:

• save cache before install/test
• gop install/test bugfix: Skip unknown switches
• gop run bugfix: keep current dir unchanged