update test file

Author: dehann

test/test_defVariable.jl

@@ -16,10 +16,10 @@ macro defVariable(structname, manifold)
   return esc(quote
       Base.@__doc__ struct $structname <: InferenceVariable end
 
-      @assert ($manifold isa Manifold) "@defVariable of "*string($structname)*" requires that the "*string($manifold)*" be a subtype of `ManifoldsBase.AbstractManifold`"
+      @assert ($manifold isa AbstractManifold) "@defVariable of "*string($structname)*" requires that the "*string($manifold)*" be a subtype of `ManifoldsBase.AbstractManifold`"
 
       # manifold must be is a <:Manifold
-      Base.convert(::Type{<:Manifold}, ::Union{<:T, Type{<:T}}) where {T <: $structname} = $manifold 
+      Base.convert(::Type{<:AbstractManifold}, ::Union{<:T, Type{<:T}}) where {T <: $structname} = $manifold 
 
       getManifold(::Type{M}) where {M <: $structname} = $manifold
       getManifold(::M) where {M <: $structname} = getManifold(M)