Fix typos in divergence notebook (#3224)

Author: choucavalier

docs/source/notebooks/Diagnosing_biased_Inference_with_Divergences.ipynb

@@ -137,7 +137,7 @@
     "  y ~ normal(theta, sigma);\n",
     "}\n",
     "```\n",
-    "Similarly, we can easily implemented it in `PyMC3`"
+    "Similarly, we can easily implement it in `PyMC3`"
    ]
   },
   {
@@ -198,7 +198,7 @@
    "source": [
     "In the [original post](http://mc-stan.org/documentation/case-studies/divergences_and_bias.html) a single chain of 1200 sample is applied. However, since split $\\hat{R}$ is not implemented in `PyMC3` we fit 2 chains with 600 sample each instead.  \n",
     "\n",
-    "The Gelman-Rubin diagnostic $\\hat{R}$ doesn’t indicate any problems (values are all close to 1). You could try re-running the model with a different seed and see if this still holds."
+    "The Gelman-Rubin diagnostic $\\hat{R}$ doesn’t indicate any problem (values are all close to 1). You could try re-running the model with a different seed and see if this still holds."
    ]
   },
   {
@@ -1816,7 +1816,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.6.3"
+   "version": "3.6.5"
   }
  },
  "nbformat": 4,