Tag Clp.jl v0.3.1

[attobot]

Repository: JuliaOpt/Clp.jl
Release: v0.3.1
Diff: vs v0.3.0
requires vs v0.3.0: no changes
cc: @mlubin

[mlubin]

Dunno the reason for this failure:

INFO: Checking repository tags...
ERROR: LoadError: LoadError: Do not modify existing published tag sha1 files (policy 8).
Ask for an exception if absolutely necessary, but tag commits
should be immutable once published for reproducibility.
 in macro expansion; at /home/travis/build/JuliaLang/METADATA.jl/.test/check-pr.jl:75 [inlined]
 in anonymous at ./<missing>:?
 in include_from_node1(::String) at ./loading.jl:488 (repeats 2 times)
 in eval(::Module, ::Any) at ./boot.jl:234
 in process_options(::Base.JLOptions) at ./client.jl:242
 in _start() at ./client.jl:321
while loading /home/travis/build/JuliaLang/METADATA.jl/.test/check-pr.jl, in expression starting on line 72
while loading /home/travis/build/JuliaLang/METADATA.jl/.test/METADATA.jl, in expression starting on line 241

[tkelman]

I think there's a race condition or some other bug in the check code. Not sure what causes it.