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##### SUMMARY
<!--- Explain the problem briefly below -->
Hi, i am trying to read a secret from the following path
        secret: "{{ lookup('hashi_vault', 'namespace={{NAMESPACE}} secret={{ BRAND }}/{{ ENVIRONMENT }}/secrets/placeholder:foo url={{ VAULT_ADDR }} auth_method={{ VAULT_AUTH_METHOD }} role_id={{ VAULT_ROLE_ID }} secret_id={{ VAULT_SECRET_ID }}')}}"

but this fails with no secret found at location. 
we are using enterprise and this uses the KV engine

vault kv get {{ BRAND }}/{{ ENVIRONMENT }}/secrets/placeholder:foo


##### ISSUE TYPE
- Bug Report
unable to read from kv data store

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
hashi_vault

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
2.8
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below

```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->


##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
```yaml

```

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##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->


##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below

```

def run(self, terms, variables=None, **kwargs):
        if not HAS_HVAC:
            raise AnsibleError("Please pip install hvac to use the hashi_vault lookup module.")
        vault_args = terms[0].split()
        vault_dict = {}
        ret = []
        for param in vault_args:
            try:
                key, value = param.split('=')
            except ValueError:
                raise AnsibleError("hashi_vault lookup plugin needs key=value pairs, but received %s" % terms)
            vault_dict[key] = value
        if 'ca_cert' in vault_dict.keys():
            vault_dict['cacert'] = vault_dict['ca_cert']
            vault_dict.pop('ca_cert', None)
        vault_conn = HashiVault(**vault_dict)
        for term in terms:
            key = term.split()[0]
            value = vault_conn.get()
            ret.append(value)
        return ret