[ci] Add the C test suite via Cake to Travis and AppVeyor.
[ci] Add the C test suite via Cake to Travis and AppVeyor.

jonathanpeppers/Embeddinator-4000,mono/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,mono/Embeddinator-4000,mono/Embeddinator-4000,mono/Embeddinator-4000,mono/Embeddinator-4000,mono/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,mono/Embeddinator-4000