v1.6.3

Gurobi v1.6.3

Diff since v1.6.2

Merged pull requests:

• Correct small typo in README.md (#606) (@brunomarct)
• Add PrecompileTools.jl (#608) (@odow)
• Prep for v1.6.3 (#609) (@odow)
• Fix precompilation when Gurobi is not installed (#610) (@odow)
• Remove unnecessary libgurobi constant (#611) (@odow)

Closed issues:

• Enable Writing of Models with Callback Functions (#605)