bundle_context class to bundle_context AR Model

[SaravShah]

When method by method and moved over methods in BundleContextTemp to
BundleContext AR model. Included validations as well has methods that
are used throughou the application.

Wrote RSpect tests for the methods moved over, and left ticket numbers
on outstanding work.

closes #176
closes #182

[coveralls]

Pull Request Test Coverage Report for Build 742

• 35 of 37 (94.59%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+1.2%) to 67.817%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
app/models/bundle_context.rb	35	37	94.59%

Totals
Change from base Build 741:	1.2%
Covered Lines:	609
Relevant Lines:	898

---

💛 - Coveralls

[jmartin-sul]

a bunch of comments, but they're all nitpicks. i'd like to see them all addressed (even if just to say they're all non-issues), but i'd also be happy to see this merged and to see any changes made in follow-on issues/PRs.

[ndushay]

buncha comments perhaps worthy of follow-on tickets and one possible discussion about config/project stuff (better F2F than on here)

[ndushay]

hrmm - not sure I agree, as reading the file from the user supplied location is needed to flesh out the bundle context data ...

Also - why is this a class method? should it be a private instance method directly operating on path_in_bundle(manifest) ? I think this is the only place where we read a csv file, unless @atz envisions writing out discovery report data as a csv (which could be a good idea, if folks work with the old discovery report that way - as it was designed)

[jmartin-sul]

ah, i'd left this comment a while back (after splitting out BundleContext from Bundle, but before sarav moved it to its own file). at that time, Bundle also used import_csv. but i just looked, and it doesn't use it any longer. so yeah, now it could just be a private instance method in this class, which is now a logical home for it.

i think that also means we can get rid of this delegation, and the require 'csv' at the top of bundle.rb:
https://github.com/sul-dlss/pre-assembly/blob/master/app/lib/pre_assembly/bundle.rb#L3
https://github.com/sul-dlss/pre-assembly/blob/master/app/lib/pre_assembly/bundle.rb#L41-L43

[jmartin-sul]

cleaned up in #244