BREAKING: replace custom build scripts with nix

General:
- Switched to yarn to better work with nix-based tooling
- Switched package system to use nix. This stops double dependencies and slow cloud compile times, while providing more compile/runtime support to the Nix project
- Removed container builder in favor of internal container tooling
- Package versions no-longer need to be SemVer compliant
- Removed "piston package spec" files, replaced with nix-flake based runtimes
- Exported nosocket and piston-api as packages within the nix-flake
- Removed repo container
- Switched docker building to nix-based container outputting
- Removed docker compose as this is a single container
- Removed package commands from CLI

Packages:
- Move bash, clojure, cobol, node, python2, python3 to new format
- Remainder of packages still need to be moved

v2 API:
- Removed "version" specifier. To select specific versions, use the v3 api
- Removed "/package" endpoints as this doesn't work with the new nix-based system

v3 API:
- Duplicate of v2 API, except instead of passing in a language name an ID is used intead.

runtimes/scaffold.sh

@@ -0,0 +1,37 @@
+#!/usr/bin/env sh
+
+if [[ $# -eq 0 ]]; then
+    echo "Usage: $0 <language name> [runtime name]"
+    echo
+    echo "language name: The name of the language to add, e.g. javascript"
+    echo "runtime name: The name of the runtime to add, e.g. node"
+    echo "  In most cases runtime won't be required, e.g. python3 is both a language and runtime"
+    exit 1;
+fi
+
+LANGUAGE=$1
+RUNTIME=$1
+NAME=$1
+
+if [[ $# -eq 2 ]]; then
+    RUNTIME=$2
+    NAME=$LANGUAGE-$RUNTIME
+fi
+
+
+if grep "./$NAME.nix" default.nix > /dev/null; then
+    echo "ERROR: $NAME already exists"
+    echo "Remove it from default.nix and retry if this is intended"
+    exit 1
+else
+    sed -i '$d' default.nix
+    echo "    \"$NAME\" = import ./$NAME.nix args;" >> default.nix
+    sed -e 's/%LANGUAGE%/'"$LANGUAGE"'/g' \
+        -e 's/%RUNTIME%/'"$RUNTIME"'/g' \
+        .scaffold.nix > $NAME.nix
+    git add $NAME.nix
+    echo "}" >> default.nix
+
+    echo "Scaffolded $NAME"
+    echo "Edit $NAME.nix to get started"
+fi