v3 API fixes, move all commands to use v3
Remove dev version expiration.

Dev installations will no longer expire after 2 weeks. However, removing
that code allows for full cross-compilation as the path-detecting code
relied on native platform-specific C code.
fix restart to match v3 API
For dyno age, use UpdatedAt instead of CreatedAt.

UpdatedAt represents the time the dyno last changed state, and is the
field used by the ruby Heroku CLI in `ps` output.
Attempt to fix Windows updating

Move old executable prior to putting a new one in its place.
.exe for windows, return rename error
fix oldExecPath
fix oldExecPath again
always return original error after install failure
cleanup oldExecPath
fix an issue where hk update would fail on windows + go fmt
go fmt
Avoid caching app
Return environment variable HKAPP if set
Parse app parameter if given
Avoid allowing app parameter per command
Inline constants
Use single variable
Remove comment
go fmt