Label shouldn't be displayed when equal to upper boundary

[alfetopito]

Description

Fixes #224

Before:

After:

To Test

1. On deploy page, insert the following values:
2. lowest price: 0.95
3. start price: 0.99
4. highest price: 1

• [ ] Check the brackets view does not overlap

Background

N/A

[ghost]

Travis automatic deployment:

• 🔐 Safe app link: To be added as a custom app on Safe Multisig Rinkeby, Mainnet or xDai
• 📖 Storybook: Component stories