Update for bevy 0.4

[darthdeus]

Bevy 0.4 was released a few days ago, and seems this library doesn't work with it because of the hard dependency on 0.3

error: failed to select a version for `shaderc-sys`.
    ... required by package `shaderc v0.6.3`
    ... which is depended on by `bevy_render v0.3.0`
    ... which is depended on by `bevy v0.3.0`
    ... which is depended on by `bevy_tiled_prototype v0.1.0 (https://github.com/StarArawn/bevy_tiled.git?branch=master#1506b554)`
    ... which is depended on by `shadows-rs v0.1.0 (C:\dev\shadows-rs)`
versions that meet the requirements `^0.6.3` are: 0.6.3

the package `shaderc-sys` links to the native library `shaderc`, but it conflicts with a previous package which links to `shaderc` as well:
package `shaderc-sys v0.7.0`
    ... which is depended on by `shaderc v0.7.0`
    ... which is depended on by `bevy_render v0.4.0 (https://github.com/bevyengine/bevy?branch=master#3b2c6ce4)`
    ... which is depended on by `bevy_gltf v0.4.0 (https://github.com/bevyengine/bevy?branch=master#3b2c6ce4)`
    ... which is depended on by `bevy_internal v0.4.0 (https://github.com/bevyengine/bevy?branch=master#3b2c6ce4)`
    ... which is depended on by `bevy v0.4.0 (https://github.com/bevyengine/bevy?branch=master#3b2c6ce4)`
    ... which is depended on by `shadows-rs v0.1.0 (C:\dev\shadows-rs)`

[framp]

I've a PR for this: https://github.com/StarArawn/bevy_tiled/pull/30

[dmtaub]

bevy-0.4 branch