[native_toolchain_c] Publish 0.7.0 (dart-lang#1841)

[native_assets_cli] Publish 0.10.0 (dart-lang#1840)

[native_assets_builder] Publish 0.10.0 (dart-lang#1842)

Publish package:native_toolchain_c as 0.6.0 (dart-lang#1699)

Return null when calling `toString` on a null object (dart-lang#1693)

Publish package:native_assets_builder as 0.9.0 & use published depend…

…encies of package:native_assets_cli (dart-lang#1695)

Publish `0.5.4` (dart-lang#1559)

* Publish `0.5.4`

* Move methods around

Publish `0.8.0` (dart-lang#1558)

* Publsh `0.8.0`

* Revert example

Publish `0.8.3` (dart-lang#1560)

* Publish `0.5.4`

* Move methods around

* Fix pubspec

* Set test data to new version

[native_toolchain_c] Publish 0.5.3 (dart-lang#1496)