v0.6.2

1. Include Smith-Wilson and Hermite cubic spline for spot curve interpolation

2. Important announcement for 0.6.2:

Starting with 1.0.0, the next version, ESGtoolkit will be renamed as lower case esgtoolkit or else (to finally remove all my active packages from CRAN).

Because:

• gaslighting (questioning people’s sanity)
• https://thierrymoudiki.github.io/blog/2020/10/16/r/esgtoolkit-new-cran
• https://twitter.com/RaphaelS101/status/1506321629797883912
• other well-documented Rip***ades & co