v0.2.1

TNRKit v0.2.1

Diff since v0.2.0

Merged pull requests:

• Impurity HOTRG (#105) (@Adwait-Naravane)
• Fix CFT spectrum per sector calculation (#106) (@Yue-Zhengyuan)
• Refactor _step_hotrg(3d)_x(y) (#107) (@Yue-Zhengyuan)
• Test on julia 1 and lts (#108) (@VictorVanthilt)