Merge pull request #530 from LCSB-BioCore/mo-change-objective

added `change_objective!` function and tests
6 jobs for develop in 5 minutes and 21 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Test
passed doc-tests:julia1.6 #319169

00:02:11

failed linux:julia1.5 #319167
slave01

00:04:14

passed linux:julia1.6 #319168
slave02

00:05:19

 
  Documentation Assets
passed documentation-assets:gource #319170
privileged

00:01:56

 
  Documentation
skipped pages #319171
 
  Test Compat
skipped trigger #319172
privileged
 
Name Stage Failure
failed
linux:julia1.5 Test
Stacktrace:
[1] pkgerror(::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.5/Pkg/src/Types.jl:52
[2] test(::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}; coverage::Bool, julia_args::Cmd, test_args::Cmd, test_fn::Nothing) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.5/Pkg/src/Operations.jl:1578
[3] test(::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}; coverage::Bool, test_fn::Nothing, julia_args::Cmd, test_args::Cmd, kwargs::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.5/Pkg/src/API.jl:327
[4] #test#61 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.5/Pkg/src/API.jl:67 [inlined]
[5] test(; name::Nothing, uuid::Nothing, version::Nothing, url::Nothing, rev::Nothing, path::Nothing, mode::Pkg.Types.PackageMode, subdir::Nothing, kwargs::Base.Iterators.Pairs{Symbol,Bool,Tuple{Symbol},NamedTuple{(:coverage,),Tuple{Bool}}}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.5/Pkg/src/API.jl:80
[6] top-level scope at none:1
Cleaning up project directory and file based variables
ERROR: Job failed: exit status 1