Roadmap for release 0.6.2

[raphaelvallat]

The following issues and PRs should be merged:

• #74 and #76
• #73 and #75
• #71
• #82 (see #89)
• #85
• #83
• #70
• #68 and #14

New dependencies

• MNE>0.23
• SleepECG