v0.7.0

EnsembleKalmanProcesses v0.7.0

Diff since v0.6.0

Merged pull requests:

• Add localization kernels. (#137) (@ilopezgp)
• Organize localizers into module, add randomized localizer (#139) (@ilopezgp)
• Update SEKI docs, add Localizers API docs (#140) (@ilopezgp)
• Improve precision of positive definiteness in sampling (#143) (@ilopezgp)