for-each-key v2.0.0

feature

• (for-each-key) drop support of node < 4
• (package) redrun v7.0.3
• (package) nyc v13.1.0
• (package) sinon, sinon-called-with-diff -> @cloudcmd/stub
• (package) eslint v5.0.0
• (package) sinon v6.0.0
• (package) sinon v5.0.3