[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

docs/bqplot.ipynb

@@ -20,7 +20,6 @@
     "from bqplot import *\n",
     "\n",
     "import numpy as np\n",
-    "import pandas as pd\n",
     "\n",
     "np.random.seed(0)\n",
     "\n",
@@ -118,7 +117,6 @@
     "from bqplot import *\n",
     "\n",
     "import numpy as np\n",
-    "import pandas as pd\n",
     "\n",
     "np.random.seed(0)\n",
     "y1 = np.cumsum(np.random.randn(150)) + 100.\n",