Allow installation with pip

[SarthakJariwala]

This will let ezconda track the pip dependencies installed in the environment.

# will do 'pip install typer` in 'test' conda environment
ezconda install -n test typer --pip

The user can obviously simply do this as pip install typer but doing it with ezconda will also write it to environment.yml file as well as environment.lock file.

Could also potentially add the functionality to search for the package on conda with this command and if it is available, suggest the user to install the conda version?

[SarthakJariwala]

Can potentially utilize conda run -n <env-name> python -m pip install <package> for pip installations

[SarthakJariwala]

It probably makes more sense to use this with the -c or --channel option.

ezconda install -c pip typer
# OR
ezconda install -c pypi typer

[SarthakJariwala]

To Do:

• Update install command to allow installation with pip
• Add new packages to pip section in specifications file
• Check if python is installed before allowing pip installation
• Update remove command to allow removal with pip
• Remove packages from pip section in specifications file
• Update upgrade command to allow pip install -U for installed pacakges
• Allow installing pip packages while installing from lockfile