adding the possibility to call others tasks from a task

[gulien]

This PR enable calling others tasks from a task within the same context.

orbit.yml:

tasks:
  - use: app
  - run:
      - {{ run "render" "upload" }}
      - echo "done!"

  - use: render
  - run:
      - cmd

  - use: upload
  - run:
      - cmd

Fixes #24

[gulien]

@j-vizcaino this solution is ok for your issue? 😄

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@e8ee541). Click here to learn what that means.
The diff coverage is 89.47%.

@@            Coverage Diff            @@
##             master      #32   +/-   ##
=========================================
  Coverage          ?   92.56%           
=========================================
  Files             ?        7           
  Lines             ?      242           
  Branches          ?        0           
=========================================
  Hits              ?      224           
  Misses            ?       10           
  Partials          ?        8

Impacted Files	Coverage Δ
app/generator/funcmap.go	75% <100%> (ø)
app/generator/generator.go	90.24% <100%> (ø)
app/runner/runner.go	94.36% <88.57%> (ø)

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[j-vizcaino]

Yes, this looks really good! Thank you very much!
I will give this a try and let you know if this works for my use-case.

[j-vizcaino]

Works perfectly!
Thanks! 👍

[gulien]

Great! Thank you for the feedback :)