RFC: Update contour usage

[tomasaschan]

This updates the usage of Contour to the new API introduced v0.1.0, since the old API was removed in a v0.2.0 which is about to be tagged.

I wasn't able to get the tests to pass locally, but I'm not sure it's related to this change; if it is, I don't understand how. If the tests don't pass the CI builds here, I'd be glad for any help in figuring out why.

[tomasaschan]

This might also be helpful for #866.

[tlnagy]

Running on julia v0.4.6 and using latest master of compose, the test fails (using this PR) here:

Rendering contour_function on pgf backend.
FAILED!
ERROR: LoadError: The following aesthetics are required by Geom.line to be of equal length: x, y, color, group

 in error at /usr/local/Cellar/julia/0.4.6_1/lib/julia/sys.dylib
 in assert_aesthetics_equal_length at /Users/tamasnagy/.julia/v0.4/Gadfly/src/aesthetics.jl:182
 in render at /Users/tamasnagy/.julia/v0.4/Gadfly/src/geom/line.jl:73
 in render at /Users/tamasnagy/.julia/v0.4/Gadfly/src/geometry.jl:48
 in render_prepared at /Users/tamasnagy/.julia/v0.4/Gadfly/src/Gadfly.jl:864
 in render at /Users/tamasnagy/.julia/v0.4/Gadfly/src/Gadfly.jl:803
 in draw at /Users/tamasnagy/.julia/v0.4/Gadfly/src/Gadfly.jl:913
 [inlined code] from util.jl:155
 in run_tests at /Users/tamasnagy/.julia/v0.4/Gadfly/test/runtests.jl:139
 in include at /usr/local/Cellar/julia/0.4.6_1/lib/julia/sys.dylib
 in include_from_node1 at /usr/local/Cellar/julia/0.4.6_1/lib/julia/sys.dylib
 in process_options at /usr/local/Cellar/julia/0.4.6_1/lib/julia/sys.dylib
 in _start at /usr/local/Cellar/julia/0.4.6_1/lib/julia/sys.dylib
while loading /Users/tamasnagy/.julia/v0.4/Gadfly/test/runtests.jl, in expression starting on line 183
===================================================[ ERROR: Gadfly ]====================================================

failed process: Process(`/usr/local/Cellar/julia/0.4.6_1/bin/julia --check-bounds=yes --code-coverage=none --color=yes /Users/tamasnagy/.julia/v0.4/Gadfly/test/runtests.jl`, ProcessExited(1)) [1]

========================================================================================================================

The current release of Compose is broken, but the problem is fixed on master. That might've been your problem.

[tomasaschan]

The last CI build failed because the new tags for Contour hadn't been merged to METADATA.jl yet; this has happened now (JuliaLang/METADATA.jl#5901) so it might be worthwhile to restart the tests here and see what happens.

[tlnagy]

Can you close and re-open to trigger a new build?

[tomasaschan]

Neat, didn't know I could trigger a restart that way. Now the error seems consistent with what you saw.

I'm having some trouble testing this on my work station (running Windows and not being able to find libfontconfig) but I can hopefully get to it on my linux laptop to fix the missing pieces this weekend.

[shashi]

looks like this also needs to repeat like you do with groups?

[shashi]

I merged this branch in and made a fix at #870

[tomasaschan]

Good catch! I also made a fix on this branch, but if you've already fixed that then this can be ignored.

[coveralls]

Changes Unknown when pulling b9f1364 on tlycken:update-contour-usage into * on dcjones:master*.

[tomasaschan]

This now fails because - nightly in Travis has changed meaning from 0.5 to 0.6; I guess a rebase might fix this, but I also think that this PR could be replaced by #870 if/when that gets merged.

Edit: merged already. Case closed :)

[shashi]

I just enabled 0.5 on travis. Tests are running https://travis-ci.org/dcjones/Gadfly.jl/builds/153203929