Better support for homogenous lists

[RiyaJohn]

Issue: #323
Closes #323
Explanation of what this pull request does.
@pelletier
I added logic of GetArray for homogenous lists as getArray func, but need your guidance:

1. Current changes fails the test cases for Unmarshal support. You wanted a separate function GetArray that users can directly use, but that will mean reusing GetPath() logic again in GetArray with getArray add-on. Is that okay?
2. Can you also review the getArray logic

More detailed description of the decisions being made and the reasons why (if the patch is non-trivial).

[RiyaJohn]

@pelletier Please ignore the first 3 commits, not sure why my old PR commits still show up. Files changes only has changes for this pr

[pelletier]

Thank you for looking at this! I think the behavior of GetPath should not change (hence why I'd like a new GetArray function. You're right that there will be a duplicate in the way traversing the tree works. I'm ok with it at the moment (eventually we should have a generic way to walk the tree).

[codecov]

Codecov Report

Merging #377 into master will decrease coverage by 0.80%.
The diff coverage is 63.93%.

@@            Coverage Diff             @@
##           master     #377      +/-   ##
==========================================
- Coverage   95.34%   94.53%   -0.81%     
==========================================
  Files          10       10              
  Lines        2318     2379      +61     
==========================================
+ Hits         2210     2249      +39     
- Misses         68       86      +18     
- Partials       40       44       +4     

Impacted Files	Coverage Δ
toml.go	80.59% <63.93%> (-4.92%)	⬇️

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[RiyaJohn]

@pelletier I did not add test cases for homogeneous lists of ints and floats because it picks say, int64 or int32 based on system spec. Hence, test coverage decreases, otherwise all checks have passed. Please review pr and let me know if any changes required

[x-hgg-x]

I think toml integers are always parsed to int64 and toml floats are always parsed to float64, so you might safely ignore the cases for int, int32 and float32 (the tree should not contain these types).

Spec:
For integers: 64 bit (signed long) range expected (−9,223,372,036,854,775,808 to 9,223,372,036,854,775,807)

For floats: Floats should be implemented as IEEE 754 binary64 values

[RiyaJohn]

I think toml integers are always parsed to int64 and toml floats are always parsed to float64, so you might safely ignore the cases for int, int32 and float32 (the tree should not contain these types).

Spec:
For integers: 64 bit (signed long) range expected (−9,223,372,036,854,775,808 to 9,223,372,036,854,775,807)

For floats: Floats should be implemented as IEEE 754 binary64 values

That's great input, thank you. Will make changes