Symlink boa into condabin

[gregfreeman]

• [ x] I read the conda-forge documentation and could not find the solution for my problem there.

Issue:
boa that is installed in the base environment is not accessible from another conda environment.
Should boa work like mamba and conda build?

Conda build's access gets included by conda's location in condabin.

mamba gets sim linked on linux here:
https://github.com/conda-forge/mamba-feedstock/blob/master/recipe/build.sh

Environment (conda list):

```

(ros2) greg@greg5:/Downloads$ which mamba
/opt/greg/mambaforge/condabin/mamba
(ros2) greg@greg5:/Downloads$ ls -l /opt/greg/miniconda3/condabin
total 4
-rwxrwxr-x 1 greg greg 521 Jul 17 11:46 conda
lrwxrwxrwx 1 greg greg 12 Jul 17 11:46 mamba -> ../bin/mamba
(ros2) greg@greg5:~/Downloads$ ls -l /opt/greg/mambaforge/condabin
total 4
-rwxrwxr-x 1 greg greg 521 Jul 19 12:00 conda
lrwxrwxrwx 1 greg greg 12 Jul 19 12:00 mamba -> ../bin/mamba

(ros2) greg@greg5:~/Downloads$ conda list boa -n base

packages in environment at /opt/greg/mambaforge:

Name Version Build Channel

boa 0.6.2 py39hf3d152e_0 conda-forge

<br/>
Details about  <code>conda</code> and system ( <code>conda info</code> ):
<details>

Note have both miniconda and mambaforge installed.   
Saw same behaviour with only miniconda installed too.   

$ mamba info

</details>
     active environment : base
    active env location : /opt/greg/miniconda3
            shell level : 1
       user config file : /home/greg/.condarc
 populated config files : /home/greg/.condarc
          conda version : 4.10.3
    conda-build version : 3.21.4
         python version : 3.8.10.final.0
       virtual packages : __linux=5.4.0=0
                          __glibc=2.31=0
                          __unix=0=0
                          __archspec=1=x86_64
       base environment : /opt/greg/miniconda3  (writable)
      conda av data dir : /opt/greg/miniconda3/etc/conda
  conda av metadata url : None
           channel URLs : https://conda.anaconda.org/conda-forge/linux-64
                          https://conda.anaconda.org/conda-forge/noarch
                          https://conda.anaconda.org/robostack-experimental/linux-64
                          https://conda.anaconda.org/robostack-experimental/noarch
                          https://repo.anaconda.com/pkgs/main/linux-64
                          https://repo.anaconda.com/pkgs/main/noarch
                          https://repo.anaconda.com/pkgs/r/linux-64
                          https://repo.anaconda.com/pkgs/r/noarch
          package cache : /opt/greg/miniconda3/pkgs
                          /home/greg/.conda/pkgs
       envs directories : /opt/greg/miniconda3/envs
                          /home/greg/.conda/envs
               platform : linux-64
             user-agent : conda/4.10.3 requests/2.26.0 CPython/3.8.10 Linux/5.4.0-77-generic ubuntu/20.04.2 glibc/2.31
                UID:GID : 1000:1000
             netrc file : None
           offline mode : False

[gregfreeman]

related to conda-forge/mamba-feedstock#13