Set up axios middleware.

Will camelize/decamelize each request. Default axios will be replaced
with this.

src/api/api.ts

+import axios, { AxiosRequestConfig, AxiosResponse } from 'axios';
+import { camelizeKeys, decamelizeKeys } from 'humps';
+
+const api = axios.create();
+
+// Axios middleware to convert all api responses to camelCase
+api.interceptors.response.use((response: AxiosResponse) => {
+  if (
+    response.data &&
+    response.headers['content-type'] === 'application/json'
+  ) {
+    response.data = camelizeKeys(response.data);
+  }
+  return response;
+});
+// Axios middleware to convert all api requests to snake_case
+api.interceptors.request.use((config: AxiosRequestConfig) => {
+  const newConfig = { ...config };
+  newConfig.url = `api/${config.url}`;
+  if (newConfig.headers['Content-Type'] === 'multipart/form-data')
+    return newConfig;
+  if (config.params) {
+    newConfig.params = decamelizeKeys(config.params);
+  }
+  if (config.data) {
+    newConfig.data = decamelizeKeys(config.data);
+  }
+  return newConfig;
+});
+export default api;