MethodError: Cannot `convert` an object of type GenericAffExpr{Float64,VariableRef} to an object of type Float64

[weiqiao]

When I ran test/runtests.jl I got errors

default dual_mode: Error During Test at /home/weiqiao/MomentOpt.jl-0.2.0/test/approximate.jl:43
  Got exception outside of a @test
  MethodError: Cannot `convert` an object of type GenericAffExpr{Float64,VariableRef} to an object of type Float64
  Closest candidates are:
    convert(::Type{T}, !Matched::T) where T<:Number at number.jl:6
    convert(::Type{T}, !Matched::Number) where T<:Number at number.jl:7
    convert(::Type{T}, !Matched::Base.TwicePrecision) where T<:Number at twiceprecision.jl:250

and

Dual Schmuedgen: Error During Test at /home/weiqiao/workstation/MomentOpt.jl-0.2.0/test/approximate.jl:98
  Got exception outside of a @test
  MethodError: Cannot `convert` an object of type GenericAffExpr{Float64,VariableRef} to an object of type Float64
  Closest candidates are:
    convert(::Type{T}, !Matched::T) where T<:Number at number.jl:6
    convert(::Type{T}, !Matched::Number) where T<:Number at number.jl:7
    convert(::Type{T}, !Matched::Base.TwicePrecision) where T<:Number at twiceprecision.jl:250

BTW I was running on tag v0.2.0, not the master branch. The master branch has a different error.