Release v0.6.4

• load segment now has configurable averages.
• Update to dir segment to add dir_writable feature.
• status segment can now display POSIX signal name of exit code.
• Added teardown command to turn off P9k prompt.
• Fixes for P9k in Cygwin and 32-bit systems.
• Better colors in virtualization segments.
• Added 'Gopher' icon to the go_version segment.
• Improved detection in nvm
• Added option to support command status reading from piped command sequences.
• Fixed issue with visual artifacts with quick consecutive commands.
• Updated 'ananconda' segment for more uniform styling.
• rvm segment can now support usernames with dashes.
• Fixed Python icon reference in some font configurations.
• Vi mode indicator fixed.
• Fixes for Docker segment.
• Added new Docker-based testing system.
• Significant enhancements to the battery segment. Check out the README to
  read more!
• New truncation strategy that truncates until the path becomes unique.

New Segments: host and user

Provides two separate segments for host and user in case you don't wont both
in one (per the context segment).

New Segment: newline

Allows you to split segments across multiple lines.

New Segment: kubecontext

Shows the current context of your kubectl configuration.

New Segment: vpn

Shows current vpn interface.