Bump version to 0.8.0 (#1864)

Signed-off-by: Devin Petersohn <devin.petersohn@gmail.com>

README.md

@@ -6,7 +6,7 @@
 <a href="https://codecov.io/gh/modin-project/modin"><img src="https://codecov.io/gh/modin-project/modin/branch/master/graph/badge.svg" align="center"/></a>
 <a href="https://github.com/modin-project/modin/actions"><img src="https://github.com/modin-project/modin/workflows/master/badge.svg" align="center"></a>
 <a href="https://modin.readthedocs.io/en/latest/?badge=latest"><img alt="" src="https://readthedocs.org/projects/modin/badge/?version=latest" align="center"></a>
-<a href="https://pypi.org/project/modin/"><img alt="" src="https://img.shields.io/badge/pypi-0.7.4-blue.svg" align="center"></a>
+<a href="https://pypi.org/project/modin/"><img alt="" src="https://img.shields.io/badge/pypi-0.8.0-blue.svg" align="center"></a>
 </p>
 
 <p align="center"><b>To use Modin, replace the pandas import:</b></p>
@@ -40,15 +40,16 @@ scheduling computation!
 
 <p align="center">
 
-| pandas Object     | Ray Engine Coverage                                                                  | Dask Engine Coverage |
+| pandas Object     | Modin's Ray Engine Coverage                                                          | Modin's Dask Engine Coverage |
 |-------------------|:------------------------------------------------------------------------------------:|:---------------:|
-| `pd.DataFrame`    | <img src=https://img.shields.io/badge/api%20coverage-83.03%25-orange.svg> | <img src=https://img.shields.io/badge/api%20coverage-83.03%25-orange.svg> |
-| `pd.Series`       | <img src=https://img.shields.io/badge/api%20coverage-77.71%25-orange.svg> | <img src=https://img.shields.io/badge/api%20coverage-77.71%25-orange.svg> |
+| `pd.DataFrame`    | <img src=https://img.shields.io/badge/api%20coverage-90.8%25-hunter.svg> | <img src=https://img.shields.io/badge/api%20coverage-90.8%25-hunter.svg> |
+| `pd.Series`       | <img src=https://img.shields.io/badge/api%20coverage-88.05%25-green.svg> | <img src=https://img.shields.io/badge/api%20coverage-88.05%25-green.svg> |
 | `pd.read_csv`     | ✅                                               | ✅ |
 | `pd.read_table`   | ✅                                               | ✅ |
 | `pd.read_parquet` | ✅                                               | ✅ |
 | `pd.read_sql`     | ✅                                               | ✅ |
 | `pd.read_feather` | ✅                                               | ✅ |
+| `pd.read_excel`   | ✅                                               | ✅ |
 | `pd.read_json`    | [✳️](https://github.com/modin-project/modin/issues/554)                                         | [✳️](https://github.com/modin-project/modin/issues/554) |
 | `pd.read_<other>` | [✴️](https://modin.readthedocs.io/en/latest/supported_apis/io_supported.html) | [✴️](https://modin.readthedocs.io/en/latest/supported_apis/io_supported.html) |