`minpoly` `MethodError`

[nsajko]

julia> using AbstractAlgebra

julia> matrix_algebra = MatrixAlgebra(ZZ, 2)
Matrix algebra of degree 2
  over integers

julia> matrix = one(matrix_algebra)
[1   0]
[0   1]

julia> charpoly(matrix)
x^2 - 2*x + 1

julia> minpoly(matrix)
ERROR: MethodError: no method matching minpoly(::AbstractAlgebra.Generic.MatAlgElem{BigInt})

Closest candidates are:
  minpoly(::MatElem{T}) where T<:RingElement
   @ AbstractAlgebra ~/.julia/packages/AbstractAlgebra/dsta0/src/Matrix.jl:4621
  minpoly(::MatElem{T}, ::Bool) where T<:RingElement
   @ AbstractAlgebra ~/.julia/packages/AbstractAlgebra/dsta0/src/Matrix.jl:4621
  minpoly(::PolyRing{T}, ::MatElem{T}) where T<:FieldElement
   @ AbstractAlgebra ~/.julia/packages/AbstractAlgebra/dsta0/src/Matrix.jl:4399
  ...

Stacktrace:
 [1] top-level scope
   @ REPL[21]:1

[nsajko]

Works fine if matrix_space is used instead of MatrixAlgebra:

julia> using AbstractAlgebra

julia> matrix_algebra = matrix_space(ZZ, 2, 2)
Matrix space of 2 rows and 2 columns
  over integers

julia> matrix = one(matrix_algebra)
[1   0]
[0   1]

julia> charpoly(matrix)
x^2 - 2*x + 1

julia> minpoly(matrix)
x - 1

[fingolfin]

Thanks for the report. This should be resolved by #1506 once it is merged.