Adding pip install excitationsolve to ci_basic. Put ExcSolve behind try import block

Author: S-Erik

.github/workflows/ci_basic.yml

@@ -30,6 +30,7 @@ jobs:
         pip install -r requirements.txt
         # test default simulator against in-house simulator
         pip install git+https://github.com/Mikel-Ma/spex@devel
+        pip install excitationsolve
     - name: Lint with flake8
       run: |
         pip install flake8

src/tequila/optimizers/__init__.py

@@ -26,9 +26,6 @@ class _Optimizers:
     cls=OptimizerSciPy, minimize=minimize_scipy, methods=OptimizerSciPy.available_methods()
 )
 INSTALLED_OPTIMIZERS["gd"] = _Optimizers(cls=OptimizerGD, minimize=minimize_gd, methods=OptimizerGD.available_methods())
-INSTALLED_OPTIMIZERS["excitationsolve"] = _Optimizers(
-    cls=OptimizerExcitationSolve, minimize=minimize_excsolve, methods=OptimizerExcitationSolve.available_methods()
-)
 
 
 has_gpyopt = False
@@ -43,6 +40,18 @@ class _Optimizers:
 except ImportError:
     has_gpyopt = False
 
+has_excsolve = False
+try:
+    from tequila.optimizers.optimizer_excsolve import OptimizerExcitationSolve
+    from tequila.optimizers.optimizer_excsolve import minimize as minimize_excsolve
+
+    INSTALLED_OPTIMIZERS["excitationsolve"] = _Optimizers(
+        cls=OptimizerExcitationSolve, minimize=minimize_excsolve, methods=OptimizerExcitationSolve.available_methods()
+    )
+    has_excsolve = True
+except ImportError:
+    has_excsolve = False
+
 
 def show_available_optimizers(module=None):
     """

src/tequila/optimizers/optimizer_excsolve.py

@@ -111,7 +111,9 @@ def __call__(
         res = self.opt.minimize(E, param_values, *args, **kwargs)
 
         if self.save_history:
-            self.history.energy_calls = self.opt.energies
+            self.history.energies = self.opt.energies
+            self.history.angles = self.opt.params
+            # self.history.gradients = self.opt.energies_shiftste
 
         return SciPyResults(energy=res.fun, history=self.history, variables=res.x, scipy_result=res)
 
@@ -127,6 +129,7 @@ def minimize(
 ):
     optimize = OptimizerExcitationSolve(
         maxiter=maxiter,
+        save_parameters=True,
         *args,
         **kwargs,
     )