Add Bifunctor compose, fixes #899

[adelbertc]

No description provided.

[codecov-io]

Current coverage is 88.95%

Merging #908 into master will increase coverage by 0.82%

1. 3 files (not in diff) in ...cats/laws/discipline were deleted. more
2. 3 files (not in diff) in ...main/scala/cats/laws were deleted. more
3. 18 files (not in diff) in ...cala/cats/kernel/std were deleted. more
4. 7 files (not in diff) in ...in/scala/cats/kernel were deleted. more
5. 6 files (not in diff) in ...ala/cats/kernel/laws were deleted. more
6. 6 files (not in diff) in ...main/scala/cats/free were deleted. more
7. 2 files (not in diff) in ...in/scala/cats/syntax were deleted. more
8. 8 files (not in diff) in .../src/main/scala/cats were deleted. more
9. 6 files (not in diff) in ...main/scala/cats/free were created. more
10. 1 files (not in diff) in .../src/main/scala/cats were created. more

@@             master    #908   diff @@
=======================================
  Files           224     179     -45   
  Lines          2839    2136    -703   
  Methods        2782       0   -2782   
  Branches         52      42     -10   
=======================================
- Hits           2502    1900    -602   
+ Misses          337     236    -101   
  Partials          0       0           

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[stew]

👍

[ceedubs]

Could we add a test of the bifunctor laws for a bifunctor that is created via composition?

[ceedubs]

@adelbertc sorry I lost track of this one. I'm going to close and reopen to hopefully fix the build failure.

[ceedubs]

@adelbertc it looks like you have a compile error due to changes in master.

[ceedubs]

Nice! 👍

[ceedubs]

Should any changes happen in #1021 to correspond with this being merged?

[adelbertc]

@ceedubs Nope, that one is only concerned with type classes over unary type constructors. I have suggestions for what to do with binary type constructor composition here: #968