fix "Module not found"

[zone117x]

Closes #54

The problem was the package.json bin entry script was pointing to the compiled js in lib/ which isn't committed to the repo, and the post-install build script is not ran in certain environments.

This PR changes the bin script to load the *.ts files directly via ts-node, rather than depending on post-install scripts to behave consistently across different environments.

Testing

Test using an installation of nodejs from official packages and not from nvm -- these installation methods seem to cause a difference in how global package install scripts are ran.

Using npm global install on MacOS/Linux:

sudo npm install -g "https://github.com/blockstack/cli-blockstack#fix/global-install-bug"
blockstack make_keychain -t > new_keychain.txt

Using npm global install on Windows:

npm install -g "https://github.com/blockstack/cli-blockstack#fix/global-install-bug"
blockstack make_keychain -t > new_keychain.txt

Using npx:

npx "https://github.com/blockstack/cli-blockstack#fix/global-install-bug" make_keychain -t > new_keychain.txt

Using yarn global install:

yarn global add "https://github.com/blockstack/cli-blockstack#fix/global-install-bug" --prefix ~/
~/bin/blockstack make_keychain -t > new_keychain.txt

Reviewer note

PR includes minor type fixes required after updating to latest typescript lib.

[agraebe]

awesome! works for me on osx

[yknl]

Thanks for the fix! This was difficult to track down.