Unable to install more than one plugin at once

[wenisman]

Describe the bug
When installing more than a single plugin Kombustion will not find the first plugins but only the last one in the list in the Kombustion.yaml

To Reproduce

1. install the network plugin
2. install the serverless plugin
3. try and generate a stack

Expected behavior
A stack generation should run with no hassles using the stacks that were installed

Screenshots

➜  infrastructure kombustion add github.com/KablamoOSS/kombustion-plugin-network
➜  infrastructure kombustion add github.com/KablamoOSS/kombustion-plugin-serverless
➜  Add plugins
   └─ Found release v0.0.7 for KablamoOSS/kombustion-plugin-network
      └─ Adding plugin: github.com/KablamoOSS/kombustion-plugin-network
➜  Installing plugins
      └─ Installed github.com/KablamoOSS/kombustion-plugin-network                                  
      └─ Already installed github.com/KablamoOSS/kombustion-plugin-serverless@v0.1.2[linux/amd64]
      └─ Already installed github.com/KablamoOSS/kombustion-plugin-serverless@v0.1.2[linux/arm64]
      └─ Already installed github.com/KablamoOSS/kombustion-plugin-serverless@v0.1.2[darwin/amd64]
      └─ Already installed github.com/KablamoOSS/kombustion-plugin-serverless@v0.1.2[linux/386]
      └─ Installed github.com/KablamoOSS/kombustion-plugin-serverless
✔  Installed plugins
➜  infrastructure kombustion install                                            
➜  Install plugins
➜  Installing plugins
      └─ Already installed github.com/KablamoOSS/kombustion-plugin-network@v0.0.7[darwin/amd64]
      └─ Already installed github.com/KablamoOSS/kombustion-plugin-network@v0.0.7[linux/386]
      └─ Already installed github.com/KablamoOSS/kombustion-plugin-network@v0.0.7[linux/amd64]
      └─ Already installed github.com/KablamoOSS/kombustion-plugin-network@v0.0.7[linux/arm64]
      └─ Installed github.com/KablamoOSS/kombustion-plugin-network
      └─ Already installed github.com/KablamoOSS/kombustion-plugin-serverless@v0.1.2[linux/arm64]
      └─ Already installed github.com/KablamoOSS/kombustion-plugin-serverless@v0.1.2[darwin/amd64]
      └─ Already installed github.com/KablamoOSS/kombustion-plugin-serverless@v0.1.2[linux/386]
      └─ Already installed github.com/KablamoOSS/kombustion-plugin-serverless@v0.1.2[linux/amd64]
      └─ Installed github.com/KablamoOSS/kombustion-plugin-serverless
✔  Installed plugins
➜  infrastructure kombustion generate stacks/base.yaml                          
➜  Generate template
✖  Fatal: Plugin `github.com/KablamoOSS/kombustion-plugin-network` is not installed, but is included in kombustion.yaml
☞  Resolution: Run `kombustion install` to fix.

Desktop (please complete the following information):

• MacOS High Sierra 10.13.6
• Version 0.3.6