Update repository links from master to main branch (#2143)

* Update INTEGRATION.md

* Update Governance.md

Author: maximevtush

INTEGRATION.md

@@ -74,7 +74,7 @@ to `bank` and `staking`... more below on [customization](#Adding-Custom-Hooks)).
 
 The requirement here is that you have imported the standard sdk modules
 from the Cosmos SDK, and enabled them in `app.go`. If so, you can just look
-at [`wasmd/app/app.go`](https://github.com/CosmWasm/wasmd/blob/master/app/app.go#)
+at [`wasmd/app/app.go`](https://github.com/CosmWasm/wasmd/blob/master/app/app.go)
 for how to do so (just search there for lines with `wasm`).
 
 `wasmd` also comes with 2 custom `ante handlers`: 

x/wasm/Governance.md

@@ -30,7 +30,7 @@ Settings via sdk `params` module:
 - `code_upload_access` - who can upload a wasm binary: `Nobody`, `Everybody`, `AnyOfAddresses`
 - `instantiate_default_permission` - platform default, who can instantiate a wasm binary when the code owner has not set it 
 
-See [params.go](https://github.com/CosmWasm/wasmd/blob/master/x/wasm/types/params.go)
+See [params.go](https://github.com/CosmWasm/wasmd/blob/main/x/wasm/types/params.go)
 
 ### Init Params Via Genesis 
 
@@ -47,7 +47,7 @@ See [params.go](https://github.com/CosmWasm/wasmd/blob/master/x/wasm/types/param
 
 The values can be updated via gov proposal `MsgUpdateParams`.
 
-### Update Params Via [MsgUpdateParams](https://github.com/CosmWasm/wasmd/blob/v0.41.0/proto/cosmwasm/wasm/v1/tx.proto#L263)
+### Update Params Via [MsgUpdateParams](https://github.com/CosmWasm/wasmd/blob/main/proto/cosmwasm/wasm/v1/tx.proto)
 Example to submit a parameter change gov proposal:
 
 - First create a draft proposal using the interactive CLI
@@ -165,9 +165,9 @@ wasmd tx gov submit-proposal <proposal-json-file> --from validator --chain-id=te
 ```
 
 ### Tests
-* [params validation unit tests](https://github.com/CosmWasm/wasmd/blob/master/x/wasm/types/params_test.go)
-* [genesis validation tests](https://github.com/CosmWasm/wasmd/blob/master/x/wasm/types/genesis_test.go)
-* [policy integration tests](https://github.com/CosmWasm/wasmd/blob/master/x/wasm/keeper/keeper_test.go)
+* [params validation unit tests](https://github.com/CosmWasm/wasmd/blob/main/x/wasm/types/params_test.go)
+* [genesis validation tests](https://github.com/CosmWasm/wasmd/blob/main/x/wasm/types/genesis_test.go)
+* [policy integration tests](https://github.com/CosmWasm/wasmd/blob/main/x/wasm/keeper/keeper_test.go)
 
 ## CLI