Update Axios - fix security vulnerability

[grommett]

This PR updates Axios to v0.21.1 to fix Server-Side Request Forgery reported by npm.

┌───────────────┬──────────────────────────────────────────────────────────────┐
│ High          │ Server-Side Request Forgery                                  │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Package       │ axios                                                        │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Patched in    │ >=0.21.1                                                     │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Dependency of │ d4eb47c463686dba716203a95d8c212661058b7e97ccb8bd89abcdc6667… │
│               │ [dev]                                                        │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Path          │ d4eb47c463686dba716203a95d8c212661058b7e97ccb8bd89abcdc6667… │
│               │ > swagger-routes > axios                                     │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ More info     │ https://npmjs.com/advisories/1594                            │
└───────────────┴──────────────────────────────────────────────────────────────┘

• npm test passes

[grommett]

Ha. Looks like I beat dependabot 😏

[flowfalls]

Hi, can this be merged? @mikestead, I use swagger-routes in production and would love to just do an npm audit fix rather than a fork of this npm package.