Add :key to techs in v-for

[atomantic]

fixes issue:

WARNING in ./~/vue-loader/lib/template-compiler.js?{"id":"data-v-30277f8a"}!./~/vue-loader/lib/selector.js?type=template&index=0!./src/app/techs/Techs.vue
<tech v-for="tech in techs">: component lists rendered with v-for should have explicit keys. See https://vuejs.org/guide/list.html#key for more info.
 @ ./src/app/techs/Techs.vue 5:2-178
 @ ./~/babel-loader/lib!./~/vue-loader/lib/selector.js?type=script&index=0!./src/app/Main.vue
 @ ./src/app/Main.vue
 @ ./src/index.js

[atomantic]

squashed in.