fix(dependency): Issue of missing javax.validation:validation-api dep…

…endency while upgrading the spring cloud to Hoxton.SR12 in kork (#939)

While upgrading spring cloud to Hoxton.SR12, we encountered below errors :

> Task :fiat-github:compileJava FAILED
/fiat/fiat-github/src/main/java/com/netflix/spinnaker/fiat/roles/github/GitHubProperties.java:3: error: package javax.validation.constraints does not exist
import javax.validation.constraints.Max;
                                   ^
/fiat/fiat-github/src/main/java/com/netflix/spinnaker/fiat/roles/github/GitHubProperties.java:4: error: package javax.validation.constraints does not exist
import javax.validation.constraints.Min;
                                   ^
/fiat/fiat-github/src/main/java/com/netflix/spinnaker/fiat/roles/github/GitHubProperties.java:5: error: package javax.validation.constraints does not exist
import javax.validation.constraints.NotEmpty;
                                   ^
/fiat/fiat-github/src/main/java/com/netflix/spinnaker/fiat/roles/github/GitHubProperties.java:6: error: package javax.validation.constraints does not exist
import javax.validation.constraints.NotNull;
                                   ^
/fiat/fiat-github/src/main/java/com/netflix/spinnaker/fiat/roles/github/GitHubProperties.java:18: error: cannot find symbol
  @notempty private String baseUrl;
   ^
  symbol:   class NotEmpty
  location: class GitHubProperties
/fiat/fiat-github/src/main/java/com/netflix/spinnaker/fiat/roles/github/GitHubProperties.java:19: error: cannot find symbol
  @notempty private String accessToken;
   ^
  symbol:   class NotEmpty
  location: class GitHubProperties
/fiat/fiat-github/src/main/java/com/netflix/spinnaker/fiat/roles/github/GitHubProperties.java:20: error: cannot find symbol
  @notempty private String organization;
   ^
  symbol:   class NotEmpty
  location: class GitHubProperties
/fiat/fiat-github/src/main/java/com/netflix/spinnaker/fiat/roles/github/GitHubProperties.java:22: error: cannot find symbol
  @NotNull
   ^
  symbol:   class NotNull
  location: class GitHubProperties
/fiat/fiat-github/src/main/java/com/netflix/spinnaker/fiat/roles/github/GitHubProperties.java:23: error: cannot find symbol
  @max(100L)
   ^
  symbol:   class Max
  location: class GitHubProperties
/fiat/fiat-github/src/main/java/com/netflix/spinnaker/fiat/roles/github/GitHubProperties.java:24: error: cannot find symbol
  @min(1L)
   ^
  symbol:   class Min
  location: class GitHubProperties
/fiat/fiat-github/src/main/java/com/netflix/spinnaker/fiat/roles/github/GitHubProperties.java:27: error: cannot find symbol
  @NotNull Integer membershipCacheTTLSeconds = 60 * 10; // 10 min time to refresh
   ^
  symbol:   class NotNull
  location: class GitHubProperties
/fiat/fiat-github/src/main/java/com/netflix/spinnaker/fiat/roles/github/GitHubProperties.java:28: error: cannot find symbol
  @NotNull Integer membershipCacheTeamsSize = 1000; // 1000 github teams
   ^
  symbol:   class NotNull
  location: class GitHubProperties
12 errors

FAILURE: Build failed with an exception.

The root cause is missing javax.validation:validation-api dependency, the reason being upgrade of transitive dependency resilience4j from [1.0.0](https://mvnrepository.com/artifact/io.github.resilience4j/resilience4j-framework-common/1.0.0) to [1.7.0](https://mvnrepository.com/artifact/io.github.resilience4j/resilience4j-framework-common/1.7.0) while upgrade to Hoxton.SR12.

To fix this issue we require to explicitly implement the dependency in gradle file of respective module.

fiat-github/fiat-github.gradle

@@ -9,4 +9,5 @@ dependencies {
   implementation "com.squareup.retrofit:converter-jackson"
   implementation "com.jakewharton.retrofit:retrofit1-okhttp3-client"
   implementation "io.spinnaker.kork:kork-web"
+  implementation "javax.validation:validation-api"
 }