[BUG] Import error for lxml

**Describe the bug**
Import error `lxml not found, please install it` when calling method `pandas.read_html`

**To Reproduce**
Create a Python step and try running:
```
import pandas

def handler(pd: "pipedream"):
html = 'NameFred'
html_tables = pandas.read_html(html)
return html_tables
```

**Expected behavior**
This library is available in [PyPi](https://pypi.org/project/lxml/)