Capitalize first letters for every point in "Challenge problems"

Author: kakirastern

tutorials/notebooks/units-and-integration/units-and-integration.ipynb

@@ -330,10 +330,10 @@
     "\n",
     "$${\\rm SFR \\, [\\frac{M_{\\odot}}{yr}]} = {\\rm C \\, L_{H\\alpha} \\, [\\frac{erg}{s}]} \\, ,$$\n",
     "\n",
-    " * find a value of $C$. How does this depend on the slope and endpoints of the IMF?\n",
-    " * take a look at Appendix B of [Hunter & Elmegreen 2004, AJ, 128, 2170](http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:astro-ph/0408229)\n",
-    " * what effect does changing the power-law index or upper mass limit of the IMF have on the value of $C$?\n",
-    " * predict the effect on the value of $C$ of using a different form of the IMF, like Kroupa or Chabrier (both are lighter on the low-mass end). If you're not tired of IMFs yet, try defining a new class that implements a broken-power-law (Kroupa) or log-parabola (Chabrier) IMF. Perform the same calculations as above."
+    "find a value of $C$. How does this depend on the slope and endpoints of the IMF?\n",
+    " * Take a look at Appendix B of [Hunter & Elmegreen 2004, AJ, 128, 2170](http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:astro-ph/0408229)\n",
+    " * What effect does changing the power-law index or upper mass limit of the IMF have on the value of $C$?\n",
+    " * Predict the effect on the value of $C$ of using a different form of the IMF, like Kroupa or Chabrier (both are lighter on the low-mass end). If you're not tired of IMFs yet, try defining a new class that implements a broken-power-law (Kroupa) or log-parabola (Chabrier) IMF. Perform the same calculations as above."
    ]
   }
  ],