Rename for clarity

Signed-off-by: Maria Shaldibina <mariash@pivotallabs.com>
Simplify Container#spawn

  * remove arguments which never change
  * simplify our use of protocol class

Signed-off-by: Maria Shaldibina <mariash@pivotallabs.com>
Move ResourceLimit creation to its own method

Signed-off-by: Maria Shaldibina <mariash@pivotallabs.com>
Use new Container#resource_limits method to simplify #spawn

Signed-off-by: Maria Shaldibina <mariash@pivotallabs.com>
Allow ResourceLimits to be optional when calling #spawn

  * this enables us to use #spawn for staging tasks

Signed-off-by: Maria Shaldibina <mariash@pivotallabs.com>
Fix quotes and spacing

Signed-off-by: Maria Shaldibina <mariash@pivotallabs.com>
Cleanup comment cruft and spec ordering

Signed-off-by: Maria Shaldibina <mariash@pivotallabs.com>
Move logging statement to reduce duplicate conditional

Signed-off-by: Maria Shaldibina <mariash@pivotallabs.com>
Remove redundant log message

Signed-off-by: Maria Shaldibina <mariash@pivotallabs.com>
Add Container#link method

  * only Container has knowledge about warden protocol

Signed-off-by: Maria Shaldibina <mariash@pivotallabs.com>
Instance#promise_link uses Container

Signed-off-by: Maria Shaldibina <mariash@pivotallabs.com>
Auto-merge remote-tracking branch 'upstream/master'