Corrected two bugs and added tests for prolongation and restriction operators.

What's Changed

• 60 Memory error when creating fine anisotropic grid by @CodingAllan in #61
• 33 prolongation and restriction tests by @CodingAllan in #34
• Correct alpha_coeff value in Poisson test to 1.0 by @julianlitz in #64

Full Changelog: v1.0.2...v1.0.3