Merge hotfix/1.2.1 from master into dev

Author: lazyoracle

c3/__init__.py

@@ -1 +1 @@
-__version__ = "1.2.0"
+__version__ = "1.2.1"

setup.py

@@ -2,7 +2,7 @@
 
 setup(
     name="c3-toolset",
-    version="1.2.0",
+    version="1.2.1",
     description="Toolset for control, calibration and characterization of physical systems",
     url="http://www.q-optimize.org",
     author="q-optimize",
@@ -13,6 +13,7 @@
         "c3/generator",
         "c3/libraries",
         "c3/optimizers",
+        "c3/qiskit",
         "c3/schemas",
         "c3/signal",
         "c3/system",