To reproduce:
1. Open the attached project;
2. Click on "ToonClassic" material;
3. Change its Shininess using slide.

Expected result: value changes smoothly when Shininess value is defined with Range(min, max).
Actual result: value jumps from min value to 0.1 and from there smoothly up to max Range value if min value is less than 0.01.

Reproduced on: 5.6.4p2, 2017.1.2p2, 2017.2.0p1, 2017.3.0b8, 2018.1.0a3.

By design: "_Shininess" is a power slider (it is hard coded within Unity to use a power slider).