Small fixes and adapt tests

Author: lkdvos

src/interface/interface.jl

@@ -42,7 +42,7 @@ By default this method continues to call [`solve!`](@ref).
 """
 function solve(problem::Problem, algorithm::Algorithm; kwargs...)
     state = initialize_state(problem, algorithm; kwargs...)
-    return solve!(state, problem, algorithm; kwargs...)
+    return solve!(problem, algorithm, state; kwargs...)
 end
 
 @doc """

src/interface/state.jl

@@ -58,7 +58,7 @@ The default assumes that the current iteration is stored in `state.iteration`.
 """
 function increment!(state::State)
     state.iteration += 1
-    return s
+    return state
 end
 
 """

test/newton.jl

@@ -30,9 +30,9 @@ function initialize_state(problem::RootFindingProblem, algorithm::NewtonMethod)
     return NewtonState(0, 1.0, scs) # hardcode initial guess to 1.0
 end
 function initialize_state!(
-    state::NewtonState,
     problem::RootFindingProblem,
     algorithm::NewtonMethod,
+    state::NewtonState,
 )
     state.iteration = 0
     state.iterate = 1.0