package: fix "homepage" field
escodegen: proper `yield` operator precedence

Fixes #146.
escodegen: fix expression within yield statement precedence

See: https://github.com/Constellation/escodegen/pull/147#discussion_r8174838
test: add a "Statement" test the yield compare test
test: add `yield a = b` test

See: https://github.com/Constellation/escodegen/pull/147#issuecomment-30037591
escodegen: fix the `yield a = b` case

No need to have parenthesis around in that case.
Merge pull request #147 from TooTallNate/fix/yield-precedence

proper `yield` operator precedence