Move test_save_load_roundtrip to init file

[lgoettgens]

When running the tests with multiple workers, the FTheoryTools and QuadFormAndIso tests may fail, when they are run on a different worker than the serialization tests. This is due to the latter adding a test function test_save_load_roundtrip that is used by the former two.
My solution is to move the test_save_load_roundtrip function to a file that gets included @everywhere right before running any tests. When similar things come up in the future, we may put them there as well.
The name of the file is open for discussion.

[antonydellavecchia]

Looks good, I would just like to see if we can put the init file one level deeper and then merge

[benlorenz]

An alternative would be to add a conditional include to the relevant test files:

isdefined(Main, :test_save_load_roundtrip) || include(joinpath(Oscar.oscardir,"test","Serialization","init_tests.jl"))

This would allow running the tests separately from the main runtests without manually including that file.

[lgoettgens]

An alternative would be to add a conditional include to the relevant test files:

isdefined(Main, :test_save_load_roundtrip) || include(joinpath(Oscar.oscardir,"test","Serialization","init_tests.jl"))

This would allow running the tests separately from the main runtests without manually including that file.

That seems like a better idea. I will change this pr accordingly.

[codecov]

Codecov Report

Merging #2801 (a9775b0) into master (ebee98c) will increase coverage by 0.01%.
Report is 4 commits behind head on master.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2801      +/-   ##
==========================================
+ Coverage   73.61%   73.62%   +0.01%     
==========================================
  Files         455      455              
  Lines       64469    64514      +45     
==========================================
+ Hits        47459    47501      +42     
- Misses      17010    17013       +3     

Files Changed	Coverage
experimental/QuadFormAndIsom/test/runtests.jl	ø
experimental/FTheoryTools/test/tate.jl	100.00%