Remove snaphot warning (#473)

Author: dongreenberg

releases/Terra_0.7_New_Features_and_Changes_Guide.ipynb

@@ -506,20 +506,6 @@
     }
    },
    "outputs": [
-    {
-     "name": "stderr",
-     "output_type": "stream",
-     "text": [
-      "/Users/donny.greenberg@ibm.com/code/qiskit-terra/qiskit/providers/legacysimulators/legacyprovider.py:41: DeprecationWarning: Simulators in the LegacySimulators provider are deprecated. If you want\n",
-      " maximum compatibility, you can use those in the Simulators provider. If you want to make the most\n",
-      " of performance, consider installing the Qiskit Aer element and user the Aer provider.\n",
-      "  warnings.warn(DEPRECATION_MSG, DeprecationWarning)\n",
-      "/Users/donny.greenberg@ibm.com/code/qiskit-terra/qiskit/providers/legacysimulators/legacyprovider.py:37: DeprecationWarning: Simulators in the LegacySimulators provider are deprecated. If you want\n",
-      " maximum compatibility, you can use those in the Simulators provider. If you want to make the most\n",
-      " of performance, consider installing the Qiskit Aer element and user the Aer provider.\n",
-      "  warnings.warn(DEPRECATION_MSG, DeprecationWarning)\n"
-     ]
-    },
     {
      "data": {
       "text/plain": [