Polymake.jl 0.2.1 released

Today Polymake.jl 0.2.1 has been released.

Diff since v0.2.0

Closed issues:

• Package does not build on single core systems (#157)

Merged pull requests:

• v0.2.1 (#159) (saschatimme)
• fix compilation errors on single-core machines (#158) (kalmarek)
• return Arrays for unknown types (#156) (kalmarek)