deps: update core dependencies (#133)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [com.google.cloud:google-cloud-core](https://togithub.com/googleapis/java-core) | patch | `1.93.3` -> `1.93.5` |
| [com.google.api:gax-bom](https://togithub.com/googleapis/gax-java) | minor | `1.55.0` -> `1.56.0` |
| [com.google.cloud:google-cloud-core-bom](https://togithub.com/googleapis/java-core) | patch | `1.93.3` -> `1.93.5` |

---

### Release Notes

<details>
<summary>googleapis/java-core</summary>

### [`v1.93.5`](https://togithub.com/googleapis/java-core/blob/master/CHANGELOG.md#&#8203;1935-httpswwwgithubcomgoogleapisjava-corecomparev1934v1935-2020-05-26)

[Compare Source](https://togithub.com/googleapis/java-core/compare/v1.93.4...v1.93.5)

### [`v1.93.4`](https://togithub.com/googleapis/java-core/blob/master/CHANGELOG.md#&#8203;1934-httpswwwgithubcomgoogleapisjava-corecomparev1933v1934-2020-04-06)

[Compare Source](https://togithub.com/googleapis/java-core/compare/v1.93.3...v1.93.4)

</details>

<details>
<summary>googleapis/gax-java</summary>

### [`v1.56.0`](https://togithub.com/googleapis/gax-java/releases/v1.56.0)

[Compare Source](https://togithub.com/googleapis/gax-java/compare/v1.55.0...v1.56.0)

04-06-2020 10:29 PDT

##### New Features

-   Add ability to partially update retry settings ([#&#8203;993](https://togithub.com/googleapis/gax-java/pull/993))

##### Dependencies

-   Update grpc to 1.28.1 ([#&#8203;1013](https://togithub.com/googleapis/gax-java/pull/1013))
-   Update com.google.api:api-common to 1.9.0 ([#&#8203;992](https://togithub.com/googleapis/gax-java/pull/992))
-   Add javax.annotations dependency in bazel build to gax-grpc ([#&#8203;1000](https://togithub.com/googleapis/gax-java/pull/1000))

##### Internal / Testing Changes

-   test: make it easier to debug failures in SettingsTest ([#&#8203;994](https://togithub.com/googleapis/gax-java/pull/994))
-   build: update dependency gradle.plugin.com.dorongold.plugins:task-tree to v1.5 ([#&#8203;995](https://togithub.com/googleapis/gax-java/pull/995))
-   test: update dependency com.google.api.grpc:grpc-google-cloud-pubsub-v1 to v1.86.0 ([#&#8203;1008](https://togithub.com/googleapis/gax-java/pull/1008))

</details>

---

### Renovate configuration

📅 **Schedule**: At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

♻️ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

👻 **Immortal**: This PR will be recreated if closed unmerged. Get [config help](https://togithub.com/renovatebot/config-help/issues) if that's undesired.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

---

This PR has been generated by [WhiteSource Renovate](https://renovate.whitesourcesoftware.com). View repository job log [here](https://app.renovatebot.com/dashboard#googleapis/java-resourcemanager).

pom.xml

@@ -63,13 +63,13 @@
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
     <github.global.server>github</github.global.server>
     <site.installationModule>google-cloud-resourcemanager-parent</site.installationModule>
-    <google.core.version>1.93.3</google.core.version>
+    <google.core.version>1.93.5</google.core.version>
     <google.api-common.version>1.9.2</google.api-common.version>
-    <gax.version>1.55.0</gax.version>
+    <gax.version>1.56.0</gax.version>
     <junit.version>4.13</junit.version>
     <guava.version>29.0-android</guava.version>
     <threeten.version>1.4.4</threeten.version>
-    <google.core-http.version>1.93.3</google.core-http.version>
+    <google.core-http.version>1.93.5</google.core-http.version>
     <api-client.version>1.30.9</api-client.version>
     <easymock.version>3.6</easymock.version>
     <mockito.version>1.10.19</mockito.version>