.bin/ symlinks absolute, makes --modules-folder not portable.

[shayne]

Running kpm install --modules-folder <name> generates absolute symlinks in .bin/ which makes the parallel/concurrent workaround fail since we move the modules-folder into place as node_modules/, as a final step.

 $ ls -l node_modules/.bin
total 128
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users  102 Jul  5 09:34 babylon -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/babylon/bin/babylon.js
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users  100 Jul  5 09:34 eslint -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/eslint/bin/eslint.js
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users   95 Jul  5 09:34 flow -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/flow-bin/cli.js
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users  105 Jul  5 09:34 image-size -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/image-size/bin/image-size
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users   96 Jul  5 09:34 jest -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/jest/bin/jest.js
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users  106 Jul  5 09:34 jest-repl -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/jest-repl/bin/jest-repl.js
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users  112 Jul  5 09:34 jest-runtime -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/jest-runtime/bin/jest-runtime.js
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users   96 Jul  5 09:34 json5 -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/json5/lib/cli.js
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users  107 Jul  5 09:34 jstransform -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/jstransform/bin/jstransform
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users   91 Jul  5 09:34 mime -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/mime/cli.js
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users   97 Jul  5 09:34 mkdirp -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/mkdirp/bin/cmd.js
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users  102 Jul  5 09:34 module-deps -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/module-deps/bin/cmd.js
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users   95 Jul  5 09:34 sane -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/sane/src/cli.js
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users   97 Jul  5 09:34 semver -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/semver/bin/semver
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users   96 Jul  5 09:34 shjs -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/shelljs/bin/shjs
lrwxr-xr-x  1 sweeney  THEFACEBOOK\Domain Users  102 Jul  5 09:34 uglifyjs -> /var/folders/5p/bpr5yyxj1vxf31tcm50jz1khpsfv0q/T/nodeModules-63887/node_modules/uglify-js/bin/uglifyjs