Inches to cm conversion is not implemented

[philiptharrison]

The function is missing from rainfall_conversion.py

[philiptharrison]

The Cauchy-Schwarz Inequality
$$\left( \sum_{k=1}^n a_k b_k \right)^2 \leq \left( \sum_{k=1}^n a_k^2 \right) \left( \sum_{k=1}^n b_k^2 \right)$$