python 安装opendr 报错OSMesa

### 报错/ERROR：

```
opendr/contexts/OSMesa/include/GL/glext.h:5794:21: note: expected ‘const GLchar ** {aka const char **}’ but argument is of type ‘char **’
 GLAPI void APIENTRY glShaderSource (GLuint shader, GLsizei count, const GLchar* *string, const GLint *length);
                     ^~~~~~~~~~~~~~
/home/chandini/anaconda3/envs/NBF/compiler_compat/ld: cannot find -lOSMesa
```

### need to install Mesa

#### Ubuntu18.04 and above:
```
apt install *OSmesa*
```

#### Ubuntu16.04 and low
--
1. Download source: (i using mesa-19.2.0 )
https://gitlab.freedesktop.org/mesa/mesa

2. build source:
```
meson configure build/ -Dosmesa=classic
ninja -C build/
ninja -C build/ install
```
3. success result:
./build/src/mesa/drivers/osmesa/libOSMesa.so