v0.13.1

Commits

• 66acd84: Update LICENSE-APACHE (Neal DeBuhr)
• ad6c4aa: Adding notes and horner_fold function. (Bruce W. Lowther) #16
• 21b12b4: tests are working.. but doesn't align with the commented requirement. (Bruce W. Lowther) #16
• cd0caad: coefficient order corrected. tests working (Bruce W. Lowther) #16
• ee29f8a: Adding commenting and cleaning up tests. (Bruce W. Lowther) #16
• 29c055e: Fix Clippy lint issues in the polynomial evaluation tests (Neal DeBuhr)